ICF Costs

There is a mistaken impression that Insulated Concrete Formwork is an expensive method of construction. Indeed, simple material cost comparisons are misleading and to identify the true price to build a house in the UK overall budgets must be identified.

In fact, ICF Construction offers the most economical solution for most building projects.

Price To Build A House (UK)

Let’s compare the cost of building an ICF house to a traditional cavity wall house:

Parameters

It is not easy to directly compare ICF costs with cavity wall construction due to the number of variables involved. However, we have broken this down to demonstrate the overall price to build a house in the UK.

*Foundation and roofing costs will be similar for both types of construction.

Results

Interestingly, this analysis shows that a rendered cavity wall house is not much cheaper than a cavity house with a brick skin.

But ICF units are definitely the cheapest form of construction for a rendered house because of the saving in scaffolding costs.

Typical House with brick facing

This is a comparison of brick wall and ICF costs in the construction of a detached house:

10m x 8m (on plan)
5m high walls
180m2 of facing brick exterior walls
12 week scaffolding (time required to lay facing bricks)

Self-build house costs will reduce the cost per square metre by about £9,000.

Cavity Wall Cost	Cost £ / m2	ICF Costs	Cost £ / m2
Facing Bricks	50 – 100	ICF forms for 150mm wall	50 – 60
Cavity Insulation	25 – 30	Concrete £100 /m3	15
Lightweight blockwork	20 – 25	ICF Installation	40 – 50
Labour @ 8 m2 / day (Bricks)	35 – 40	Facing Bricks / m2	50 – 100
Labour @ 20 m2/day (l/w blocks)	15 – 20	Labour @ 8 m2 / day (Bricks)	35 – 40
Total cost per m2	145 – 215	Total cost per m2	190 – 265
Total costs	26k – 39k	Total ICF costs	34k -48k

Typical House with render

If the facing bricks are replaced with render an entirely different result is obtained. This is a comparison of the wall costs of:

10m x 8m (on plan)
5m high walls
180m2 rendered external walls
12 week scaffolding (time required to lay facing bricks)

Self-build house costs will reduce the cost per square metre by about £9,000.

Cavity Wall	Cost £ / m2	ICF Costs	Cost £ / m2
Inner skin of lightweight blocks	20 – 25	ICF forms for 150mm wall	50 – 60
Cavity Insulation	25 – 30	Concrete £100 /m3	15
Outer skin of lightweight blocks	20 – 25	ICF Installation	40 – 50
Labour @ 10 m2/day (l/w blocks)	20 – 30
Render	50 – 75	Render	50 – 75
Total cost per m2	135 – 185	Total cost per m2	155 – 200
Total costs	24k – 33k	Total ICF costs	28k – 36k
Scaffolding (12 weeks)	12k – 18k	Scaffolding (4 weeks)	4k – 6k
Total cost with scaffolding	36k – 51k	Total ICF costs with scaffolding	32k -42k

ICF: Building Better to Live Better

Ready to see what ICF can do for your next project?

Dream home? Discover how ICF creates incredibly energy-efficient, quiet and resilient homes that stand the test of time.

ICF Building Types

Industrial & Agricultural Units Costs

ICF steel rafter connection — Typical Steel Rafter to ICF Wall Connection

Steel portal frame construction has traditionally been the most cost-effective method for building industrial and agricultural units. However, economical ICF costs now offer a competitive alternative.

Most industrial units feature cavity brick walls around the perimeter, typically reaching about 2m high. This creates a strong, secure, and fire-resistant barrier around the ground floor perimeter. Above this, insulated, PVC-covered, trapezoidal steel panels extend up to the eaves and across the roof. This construction method requires pad foundations to support the portal frame stanchions.

The whole construction process can be sped up by using strip footings and ICF walls up to eaves level. The steel rafters of the portal frames are then bolted to the reinforced ICF walls that replace the steel stanchions of the portal framed alternative.

The ICF walls can be rendered to provide a fast economic way of finishing the buildings. When agricultural buildings are required to store crops the ICF can be lined with stainless steel sheets and expensive concrete retaining walls are just not required. Economical ICF costs now makes this form of construction very competitive.

Retaining Walls Costs

Garden Retaining Walls

ICF walls provide an extremely economic and rapid way of building garden walls and gravity type retaining walls up to about 3m high.
ICF can be finished with render or brick slips and will always cost a fraction of the amount that walls built with shutters or brick walls will cost.

Embedded Retaining Walls

Economical ICF costs make this type of wall very economic when a higher wall is required with good ground conditions. These are built by excavating a trench, installing a strip footing and adding ICF up to the required height. The trench is then filled so the embedded length of the wall holds the cantilever section of the wall in place.

High Retaining Walls & Limited Access

In back gardens with limited access or where the wall height is higher than 3m, king post walls built with ICF will often provide the cheapest solution.

Firstly, a line of holes is excavated using a continuous flight auger (CFA) piling rig. This can be a specialist machine, or an auger mounted on a tractor.
Once the holes have been excavated, universal column sections are installed in the holes, aligned with each other and concreted into place.
ICF wall sections are then placed over the steel posts, lined up and filled with concrete. If the posts are close enough together, the ICF walls may not need to be reinforced.
A site investigation will be required to finalise the design of any walls greater than 2m high.

In practice this is a simple, very economic way of building high retaining walls of any length.

Insulated concrete formwork

Build smarter: stay up to date with the latest industry news & icf insights

Subscribe to our newsletter for exclusive Insulated Concrete Formwork construction insights, key industry developments and updates on the constantly evolving landscape of house building in the UK.