Why you cannot find a price per square metre
Two facades with the same area can cost very differently: one has a level substrate, ground floor and two windows; the other has crumbling render, two storeys, an oriel window and twelve windows. Therefore, the price per square metre found online does not apply to your house until someone has seen it. We determine the price after a free inspection, in writing, itemised, and it remains unchanged during construction. Here is what makes up the cost.
Structure and area
The façade, roof, attic floor and plinth each have different structures and labour requirements. The attic floor insulated with blown-in insulation is the cheapest square metre on the house, while insulating a habitable attic from the inside, including vapour barrier and new lining, is among the most labour-intensive. For the façade, the actual wall area is calculated excluding windows but including reveals, window sills and plinth.
Material and thickness
White polystyrene is the cheapest, graphite slightly more expensive, mineral wool significantly more expensive and wood fibre the most expensive. Thickness is determined by calculation, not budget: thicker insulation costs more for materials, but labour, scaffolding and rendering remain the same, so the difference in total price is less than people expect.
Substrate condition
Solid old render is only primed. Crumbling render is knocked off and repaired; unevenness exceeding 20 mm per metre is levelled. A damp plinth requires remediation before insulation. The substrate condition is determined during the inspection and listed as a separate item in the estimate, so you can see exactly what you are paying for.
Building complexity and height
Every window requires reveals, sills, corner beads and diagonal reinforcement. Bay windows, balconies, cornices and roof overhangs increase labour intensity. A two-storey house needs scaffolding; for a single-storey building we can partly work from a platform. Vehicle access to the property affects material delivery.
Details and supplementary work
- New window sills, extension of rainwater downpipes and lightning conductors, relocation of outdoor lights and sockets.
- Connection to the roof at the gable end, insulation of window and door reveals, adjustment of the plinth and eaves gutter walkway.
- Paint and render type, mosaic plinth, tiling.
- Disposal of rubble and old plaster, protection of windows and the area around the house.
What you will find in our estimate
Breakdown by layers including manufacturer and thickness, areas and quantities, scaffolding, transport, waste disposal and additional works listed separately. The estimate is binding. If anything is discovered during construction that was not visible during the inspection (typically under damaged plaster), we resolve it via a written addendum before work proceeds.
Do you want to know how much insulating your house will cost? Send a few detailsWe will arrange an inspection, and within a week you will receive a quotation. Free of charge and without obligation.
Frequently Asked Questions
Why is there no price list on your website?
Because it would not be valid. The cost of insulation depends on the substrate, complexity, building height and materials, factors that differ for every house. After a free inspection, you will receive a binding itemised estimate.
Is the inspection and estimate really free of charge?
Yes. We will arrive, take measurements and within a week send you the proposed specification and budget. You sign nothing and pay nothing until you decide to award the contract.
Can the price change during construction?
The estimate is binding. It can only be changed by means of a written addendum if something is found under the old render that was not visible during the inspection, and this must always occur before the work is carried out.
Is more expensive insulation worth it?
Stronger or more efficient insulation increases the material cost, but labour, scaffolding and rendering remain the same. The difference in the total price is usually smaller than people expect, while the heating savings last for decades.