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M&E Contractors

Looking to procure a Mechanical and Electrical Contractor? Before you do, we've got something to share with you. This Value Engineering Guide focuses on the numerous technical solutions that can be found in Mechanical and Electrical. We’ve worked closely with the very best Specialist Subcontractors in the field to unearth intelligent, technical and practical solutions to improve project profitability while retaining performance of the building.

Gas vs. Electricity

M & E can be difficult to amend from a VE perspective as, in many cases, the scheme specified has been designed to comply with certain Planning Requirements such as BREEAM. The systems specified help the building to achieve a certain BREEAM score and therefore, it’s not simple to VE the package without compromising on performance to some extent. However, we would always look at the products that have been specified and the warranties that are attached to them to identify VE opportunities. So how and where can you Value Engineer M & E systems?

Centralised Plant & HIUs

To ensure you retain the BREEAM Score required by planning, typically you need to adopt an add / omit approach. One thing to focus on is the operation of plant in the building. For example, we worked on a project with 100 apartments where the specification included Centralised Plant and Heat Interface Units and we knew immediately that:
  1. The scheme was high-performing but expensive
  2. Even with Value Engineering, a high BREEAM score could be achieved
Heat Interface Units (HIU) are high performance products and they work in a similar way to a traditional Combi Boiler – i.e. they heat water directly from the mains when you turn on a tap, so there’s no need for a hot water storage cylinder or a cold-water storage tank in the roof space. We looked firstly at the HIUs that were specified and compared them to HIUs that we’ve used on previous projects over the last 3 years. Switching the HIUs on this particular project would not only save £800 per unit (£800.00 x 100 = £80,000.00) but would also deliver the end user with an extended warranty of 4-years rather than 1-year. Also, rather than each flat being independently heated directly by electricity or gas, the specification proposed to heat each flat via the flow and return water provide by a central plantroom. A centralised plant room has the benefit of reducing the environmental impact by reducing gas volume requirements and in turn, carbon emissions. This system is often chosen as a simple means of achieving a high BREEAM score, but it is expensive and there are more economical ways to deliver this. We proposed a new solution to move away from Centralised Plant and Heat Interface Units to Hot Water Cylinders and Electric Panel Heating (not storage heating but electric convector heating). This simple change delivers a major material saving: the unit price of a HIU is circa £2,500 whereas a Hot Water Cylinder and Electric convector heater is closer to £1,500k - where you have 100 apartments, that’s £100,000! Also, if everything is being heated electrically as opposed to with gas, you negate the need for gas Centralised Plant which can bring further construction savings of around £200,000.00 depending on the size of the scheme. The new system did have drawbacks; electric heating in lieu of gas had a negative impact on the BREEAM score and therefore, we had PV panels introduced to compensate. Nevertheless, we made a big saving as below:
  • Omission of Centralised Plant and HIU’s (saving £380,000)
  • Addition of Electric Panel Heating and PV Panels (add £80,000)
The BREEAM rating of the building was maintained together with a saving of £300,000!

Pipework Specification

In addition, if steel pipework is specified there are genuine chances to improve the budget and programme by moving to a pre-insulated plastic pipe which:
  1. Reduces programme
  2. Increases flexibility in design and site
  3. Reduces risk of leaks
Steel pipework is a high-quality product with a good environmental performance due its long-lasting qualities. But, it only comes in standard 6 metre sections meaning there are multiple joints and delivery costs are higher. Joints brings multiple issues:
  1. Additional labour is required to install the joint on site and
  2. There’s an increased chance of defective installation that leads to leaks and remedial works.
As a result, it’s standard practice to install leak detection at each joint – again, increasing the material cost and the time to install. Alternatively, Pre-Insulated Plastic Pipework is delivered in larger sections of up to 150 metres and it’s therefore possible to install hundreds of meters in hours as opposed to days. Because you only have two joints every 150 metres, you also reduce the need for Leak Detection and the risk of leaks full stop. The saving in time and money can often be in the hundreds of thousands. Steel pipework, is often specified for having greater life expectancy than plastic. In buildings where the mains runs at 80°c (typical temperature) steel has a life expectancy of 50 years versus 30 for plastic. Plastic Pipework can achieve 50 years however, if the mains operates below 80°c. A flow temperature of 60-70°c would increase the life expectancy of the plastic pipework to 50 years and can be achieved by the specification changes above. All of these changes requires a detailed analysis of the project specification, requirements and possible alternatives, but the savings can be substantial. On this project, we saved in the region of half a million pounds for ourselves and the client while concurrently retaining the BREEAM levels that Planning required – a success all round. This section on Gas Vs Electricity was provided in collaboration with Sustinere UK. Sustinere UK aim is to make energy efficiency and low carbon technology accessible, understandable and affordable. Sustinere UK offers turn-key feasibility, design, installation, finance and service capabilities.


Ventilation and Air conditioning are critical to delivering comfortable built environments. The quality of insulation materials are constantly increasing and buildings are better sealed than ever. Building Regulations typically require heat recovery with ventilation, and with ever improving product selection and technologies, Sick Building Syndrome is becoming something synonymous with the past. Tied closely to Building Regulations, the design of Air Conditioning and Ventilation can be complex. But, with that complexity comes opportunity. There are multiple systems available on the market, and in turn there are many Value Engineering opportunities during construction.

Integrating Ventilation with Air Conditioning

On projects with Air Conditioning, ‘traditional’ procurement sees two trades; an Air Conditioning Contractor and a separate Ventilation Contractor. One major way to save both time and money however, is to combine the two. If you integrate the trades, you will make significant savings. Rather than designing and installing two smaller systems of ductwork, you only have one, albeit larger scheme to manage. For example, consider a typical office building: you have an open plan office and individual rooms on the perimeter of the floor. A typical fresh air system would include for ductwork that comes into that floor and is then diverted in and out of each closed space/room on the perimeter. Integrating the air conditioning with the ventilation reduces the linear meterage of the ductwork required into this area. With two packages, you’d require two sets of ductwork (Fresh Air and Cooling) - the Air Conditioning contractor traditionally arrives second and installs a larger version of the ductwork installed by the ventilation contractor for the fan coils. It’s common sense that this is uneconomical and inefficient. With integration, it’s possible to eliminate duplication of ductwork. By routing the fresh air into the fan coil return plenums, you no longer need additional fresh air distribution ducts on the floor. This brings with it three benefits:
  1. Reduced material costs
  2. Reduced labour costs
  3. Reduced management and admin costs owing to fewer subcontractors
Additionally, with fewer subcontractors on site, you reduce the volume of coordination meetings and risk of non-conformities, which reduces the programme and your overall spend. This is a major Value Engineering opportunity: Main Contractors can deliver a system which performs as specified while simultaneously removing one trade from the programme and saving thousands of pounds in material and labour.

Energy Savings on Cooling

Another Value Engineering opportunity is the use of Variable Refrigerant Volume (VRV) systems in lieu of Chilled Water Systems (CWS). VRV systems are typically comparable in material cost with CWS; however, you can expect to save over 20% on the cost and programme of installation with VRV. CWS installation effectively requires multiple trades: steel and copper pipework, ductwork and mechanical. This brings with it interfacing requirements, critical path planning and of course non-conformity – all of which adds significant risk. VRV on the other hand only uses copper pipework and usually only one trade is required. In reality VRV is a simpler, less challenging installation at a lower cost than the CWS alternative. Despite this it still seems to get specified less than CWS. If you’re looking to convince the client of the benefits of VRV, this can be quite simple on projects such as Commercial Fit Outs. These schemes often have a Comms Room and each floor will have intermittently occupied spaces. With VRV the heat generated from the Comms room can actually be transferred to heat the rest of the building. If you have a sizeable Comms Room, the client could save lots of money long term, making a move to VRV attractive. The client takes a whole life cost saving and the Contractor takes a saving in time and money during construction. Integration offers the biggest potential saving in construction, and this can often be in the hundreds of thousands and weeks when it comes to programme saving. Offering this, together with a system that brings whole life cost savings, will often mean the saving in construction is all yours. Where we regularly find Value Engineering solutions for the Client in Building Control and connection with the BMS. Ventilation systems that are adaptable are those which are the most efficient. For example, many systems today are capable of being occupancy controlled (i.e. sensitive ventilation which only turns on when occupants are in a room) and this is a massive value add for the Client – if they only use a room 20% of the day, they will only ventilate it 20% of the day. Equally, with CO2 monitoring, the client can reduce ventilation rates while maintaining high air quality standards at lower costs. Variable Speed Drives and Occupancy / Air Monitoring as VE opportunity. All for the end user. This section on Ventilation was provided in collaboration with Steam Enviro. Building on more than 25 years of experience, creating engineered solutions for applications in marine, construction, mobile climate and technical control systems, Stream Enviro is a centre of excellence for bespoke environment HVAC.

Underfloor heating

As a package of works, Underfloor Heating (UFH) can actually be quite challenging to Value Engineer. Generally speaking, the systems that are specified are specified as such because they achieve a certain output required by the specification. UFH systems are pretty much specified on this basis and therefore, often hard to VE the package without compromising performance to some extent. How can you Value Engineer the Package without compromising on the performance of the system? Typically, there are two elements of an UFH package where there is scope for flexibility or over-engineering/specification by the Architect or Employer - the Acoustics and Thermal Insulation and this is where we most often do Value Engineering.

Thermal Insulation

The majority of Architects will typically include very high performing Thermal Insulation in order to ensure they best ‘cover themselves’. This over engineering / specification however, is sometimes unnecessary and delivers Value Engineering opportunities. We’ve listed a couple of examples below:

1. Thermal Insulation at Intermediate floors

Intermediate Floors do not need to achieve a U-Value because they count as party floors. Despite this, in many cases, Architects will specify the use of Polyurethane rigid foam (or PUR Insulation for short) as a high-performance insulating material. With some design calculations on the U-Values of the building, more often than not, this high-performance (and high-cost) insulation can be calculated/designed out and replaced with more economical Expanded Polystyrene Foam (EPF) insulation that still meets the performance requirements. Not only is EPF cheaper but it is also composed of individual cells of low density polystyrene, making it extraordinarily light and simple to install which can also reduce build times. More often than not, it is possible to achieve the specification which is required and also provides thermal performance.

2. Thermal Insulation at Lower/Ground Floors

On the lower floors you MUST achieve a certain U-Value because these floors are not considered party floors. Things are a bit more challenging here but a number of alternative solutions are available. Again one of the options here is to complete an add/omit calculation where the more expensive products are replaced with a simpler solution. In these areas, particularly where you have a block and beam floor, the Design team will often have included for a single layer (often 100mm) of high performing PUR insulation. An alternative design for this however, is to use two layers (2x 100mm) of lower U-Value Insulation such as Expanded Polystyrene insulation (EPS). Two layers of this insulation are equivalent in terms of performance of 100mm of the superior PUR insulation however far more economical. In addition to this, to find the extra 100mm, you would typically remove a single course of brickwork to make room for the 100mm of insulation. This means your saving can be two fold in terms of material and labour. Simply put the add/omit works as follows:
  • Omit:
    • 100mm of High Performing PUR Insulation.
    • 100mm of traditional brickwork
  • Add:
    • 200mm of EPS Insulation
  • Overall = Good Savings
Of course it is fundamental that the structural and thermal calculations are done on this to ensure the requirements are met, but if possible you can make a saving in time on the construction programme and likewise on the material purchase while still meeting the U-Value in the contract.


Acoustic Insulation can in some cases fall under the same header as Thermal Insulation and when considering Value Engineering opportunities on either, the U-Value and Acoustic Value often goes hand in hand and therefore, the above is relevant. One further area for exploration is on larger Apartment blocks where this are party floors with specific acoustic requirements. These are often over-estimated by the Design Team and a day or two of focus, in partnership with a good quality Acoustic Engineer, can more often than not highlight the over specification in thickness of Acoustic Insulation. We often invest a day to put together an Acoustic Report showing performance levels of the specification are met with reduced thickness insulation and submit this together with our design for approval. We meet the requirements and take the saving in reduced material purchase. This section on Underfloor Heating was provided in collaboration with WMS Underfloor Heating. WMS are a leading supplier and installer of underfloor heating and cooling systems for new build and refurbishment developments in the UK.

Comms Systems

With telecoms, data and security, the ability to VE elements of the work can be quite challenging due to the fact that the specification is all end-user driven. The volume of works depends solely on the equipment the user will have, so the number of connections and cables to these is difficult to manage. However, VE opportunities do exist and we’ve reviewed these on both refurbishment and new build projects where the scope of works is often totally different.

New Build Projects & Pre-Terminated Looms

New Build projects are traditionally much simpler for Comms installations – typically you have access to large open areas with Raised Access Flooring. A data cable/network installation has several VE opportunities. Traditionally, for every single device (phones, computers, printers etc.) there is an individual cable installed. The alternative is to install in bundles of up to six cables. The installation of Pre-Terminated Looms is far quicker than single cable installation as you effectively install/pull six cables at once rather than individually. In addition, these Looms are pre-terminated with a plug on the end, so there is no termination work to do either – another saving! This simple installation is faster and cheaper on site in terms of installing the cable and terminating the cables. What’s more, the termination is completed in a factory environment and subject to higher Quality Control, which reduces the likelihood of errors or non-conformities.

New Build Projects – Back-Bone Cabling

Data Networks are what we call ‘Home Run’ (i.e. the cables run from the piece of equipment to a Central Cabinet - A to B) and there is one cable for every device. This often means that saving time in installation is difficult: for example, whereas electricians can ‘daisy-chain’ their services, Data Networks cannot. There is a trick to potentially saving time on site: Back-Bone Cabling. Back-Bone Cabling is the introduction of a spine in your Network. Typically, cables are run to the Comms Cabinet on the Ground Floor which means additional material and labour costs running every cable from First to Ground, Second to Ground, Third to Ground and so on. By introducing Back-Bone cabling, you effectively introduce Comms Cabinets on every floor which reduces the project into bite-sized sections and builds a ‘spine’. This reduces the lengths of cabling required, and in turn the material and labour cost drop significantly, It also improves the integrity of the system because each floor is now independent and ring-fenced from the other, which makes identifying problems much simpler. Despite the saving in time, there are additional costs for a Comms Cabinet on every floor. This can sometimes be expensive, but the costs are often cost neutral or even outweighed when you factor in the omission of cabling costs and the impact of time on preliminary costs. In summary, Back-Bone Cabling provides a better end product for the Client and will guarantee significant savings in time on your programme so are well worth considering.

Refurbishment Projects

The installation of Comms packages can be broken down into three areas of expertise and trades:
  1. The installation of the cables
  2. The termination of the cables (sockets etc.)
  3. The connection of the cables to the systems (telephone, computers, CCTV, data networks etc.)
What many don’t understand is that the elements above are often completed by three different subcontractors who have expertise in each. One major Value Engineering opportunity is to do this with one company who have competencies across all three. It’s logical that using three subcontractors is uneconomical and inefficient and it will drive:
  1. Increased material costs
  2. Increased labour costs
  3. Increased management requirements as a result of coordination of the three trades
Using only one Subcontractor removes the need for multiplying coordination meetings, applications for payments, contract drafting and much, much more so will have a real impact on your team’s output and the critical path of the programme. This is particularly valid on refurbishment projects where there is an existing infrastructure and the scheme has live circuits. For example, a Contractor with just Cabling Installation expertise won’t be able to work on the project as post disconnection, the won’t able to re-connect. In summary, on refurbishment schemes, save time and money by using a contractor who can complete al three trades. This section on Comms Systems was provided in collaboration with Grapevine Communications. Grapevine is an independent supplier of Telephone, CCTV, Access Control systems, Network Cabling Services, Maintenance and Support.

Audio Visual

With Audio Visual (AV) and Home Automation packages, Value Engineering exercises are typically product driven. If you want to reduce costs with AV & Home Automation the easy option is to focus on product specification – if the budget is X we don’t propose a system that suits Y. Being up front with budgeting is very important and in this way, solutions can be planned to optimise your schemes. The earlier we’re involved in a project the better. It is incredibly important to understand the end-users desired use of a room as this helps us deliver the right product to their budget. In terms of Value Engineering construction specific solutions, our approach is to be proactive and plenty of forethought is used in order to reduce, not just site installation costs, but also potential costs driven from the risk of damage to expensive equipment on site. We work with luxurious kit and damage to materials can be disastrous for project budgets. For us, sequencing is therefore hugely important. AV and Home Automation works generally commence at the end of the site works and therefore, it’s almost always on the critical path. It is for this reason that we focus on two key issues when planning project installations:
  1. Manufacture and test materials off-site where possible; and,
  2. Regularly coordinate with and spot-test the Electrical Contractor’s installation
The two main risks on site are damage to materials and poor coordination, which leads to Non-Conformance Reports and delays on site – all of which come at a cost and time implication during a period when the project simply cannot afford it.

Off-Site Production & Vesting Materials

If we were to give one single piece of advice to a Project Manager of Quantity Surveyor procuring an AV and/or Home Automation package it would be to vest and build materials Off-Site. If you allow the Subcontractor to programme, test and semi-commission the equipment off-site in a controlled environment, not only do you improve the quality of the installation, but you also introduce other advantages:
  1. Reduced chance of damage on site;
  2. Reduced chance of delays on site if materials are missing during your installation, when in a factory they can be found instantly; and,
  3. Reduced on-site commissioning period as the units are pre-tested and simply installed on site.
To deliver these benefits to your project, you must be prepared to Vest materials off site as it brings with it multiple advantages and potentially zero drawbacks – if you can convince your client of the benefits (these are clear as stated above), they should support you in the valuation of materials vested in their ownership to the benefit of the project.

Coordination and Spot-Checking

In addition to Off-Site manufacture, coordination with the electrical contractor is key. Electricians are almost always on site prior to us and they run cabling on our behalf. What we do is colour code wiring to match drawings and reduce errors, but also, we arrange coordination meetings and spot-check their works regularly. It sounds simple but if you’re creating coordination meetings and spot-checking installation while at the same time, manufacturing, testing and commissioning equipment off-site, the chances are that your installation will be problem free and Practical Completion will be achieved with ease. While on the face of it, neither of these solutions are Value Engineering in a traditional sense, both are intelligent management solutions to a high-risk installation. Well-considered sequencing and off-site manufacture will save you time and therefore, money. Preliminaries are incredibly expensive and so are damages for delays – we can reduce site durations significantly with this approach. In summary, from the outset, consider Off-Site Production and Testing, it will save you huge amounts and assist in the delivery of a less-complicated Practical Completion. This section on Audio Visual was provided in collaboration with KNEKTD, a leading Specialist in Audio Visual, Automation and Data. Knektd Ltd specialises in bespoke audio visual, home automation and entertainment solutions for prime and super prime residential properties in London. Our clients include private individuals, interior designers, architects, well respected building contractors and property developers.