Value Engineering Underfloor Heating | C-Link

23 November 2018

Value Engineering Underfloor Heating

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As a package of works, Underfloor Heating (UFH) itself 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.

So 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 a 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 piece was contributed by Craig Edwards of WMS, a leading supplier and installer of underfloor heating and cooling systems for new build and refurbishment developments. Learn more about WMS.

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