Comparing the major material items
Structural materials
| In-situ reinforced concrete | Index 100, the reference. High mechanical resistance, a century-long life, direct execution possible. The precast variant is comparable in cost: a small labour saving on formwork, offset by transporting and placing the elements. |
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| Steel frame | Index 105–120 according to the steel price. Quick to erect, cutting the site duration by 20–30 %. Beware the high volatility: the steel index rose 65 % between 2020 and 2022 before falling 25 % in 2023. |
| Timber frame | Index 105–115. A dry site, shorter programmes, a favourable carbon balance. Regulatory constraints on height above two upper floors require specific engineering. Structural timber rose 70 % in 2020–2022 as global supply chains tightened. |
External joinery
| PVC double glazing | Index 100, the reference. The most widespread solution in housing. Virtually no maintenance, good standard thermal performance. |
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| Triple glazing | Index 115–125. Required or recommended by the environmental regulations for housing in the coldest zones. A significant acoustic gain. Recovered over 10–15 years through energy savings. |
| Aluminium | Index 140–180. Slender profiles, great freedom of dimension, fully recyclable. Dominant in commercial work and unavoidable for curtain walling. |
| Timber and timber-aluminium | Index 150–200. Premium appearance, maximum thermal performance. Periodic maintenance every 5–10 years on the external timber. |
| Curtain walling | Index 200–400. Reserved for commercial buildings and high-end development. Complex weatherproofing, requiring specialist design. |
Façade materials
| Render on external insulation | Index 100, the reference. The most used solution in new apartment buildings. Maintenance: redecoration every 20–30 years. |
|---|---|
| Fibre cement cladding | Index 120–140. Very low maintenance, a life beyond 40 years, great freedom of colour. Increasingly used in social housing and commercial work. |
| Timber cladding | Index 130–160. A natural appearance, a favourable carbon balance. Staining or painting every 5–10 years according to species and exposure. |
| Zinc, weathering steel, titanium-zinc | Index 180–250. A life beyond 50 years, no maintenance. Fine materials for demanding architectural projects. |
| Facing brick | Index 140–180. Exceptional durability beyond 100 years, minimal maintenance. Slower to build, being hand-laid. |
Waste factors: a key element of the real cost
The cost of a material in a project is not its catalogue price multiplied by the quantity in place. Between the quantity in place and the quantity ordered, several factors increase the figure.
Why quantities are increased
| Over-consumption | Some methods require more material than remains in place: overlapping waterproofing membranes at 5–10 %, compacting fill, a real bedding mortar thickness above the theoretical calculation. |
|---|---|
| Breakage | Inevitable for fragile materials such as tiles, ceramics and glass. According to the fragility and site conditions: 3–8 % for standard floor tiling, 5–10 % for roof tiles. |
| Cutting | Offcuts from ends of rows or adaptation to the dimensions of the room. Variable with the shape of the surfaces: 5–15 % for diagonally laid tiling against 3–6 % laid straight. |
| Packaging surplus | Materials are sold in fixed packs, pallets, boxes, bags, rolls. The quantity ordered must be a whole multiple of the pack, which almost always leaves an irreducible surplus. |
| Item | Waste factor |
|---|---|
| 300 mm tiling laid straight | 1.06 to 1.10, that is 6–10 % more |
| Tiling laid diagonally | 1.12 to 1.20, 12–20 % |
| Solid timber flooring | 1.10 to 1.15 |
| Roof tiles | 1.08 to 1.15 according to the roof form |
| Plasterboard | 1.03 to 1.07 |
| Ready-mixed concrete | 1.03 to 1.05, through formwork loss and residue |
| Reinforcement, mesh and bar | 1.05 to 1.10, through cutting offcuts and laps |
Price volatility: managing the contractual risk
Construction materials saw unprecedented price rises between 2020 and 2022, with direct effects on the profitability of sites committed before the crisis. The partial stabilisation of 2023–2024 should not obscure the fact that volatility is a durable reality of the sector.
| Steel, reinforcement and frame | Up 65 % between 2020 and mid-2022, then down 25 % in 2023. A major effect on structural and frame contracts signed at a firm price. |
|---|---|
| Structural timber | Up 70 % in 2020–2022 as North American and Nordic supply tightened. A progressive return to more normal levels through 2022–2023. |
| Copper, plumbing and electrics | Up 80 % in 2020–2022. Directly indexed to the world copper price. Alternatives exist in cross-linked polyethylene and multilayer for plumbing, and aluminium for some cabling. |
| Synthetic insulation | Heavily dependent on petrochemical energy prices. Polyurethane and polystyrene foams rose 30–60 % in 2022. |
For contracts running more than 12 months, systematically inserting a price revision clause has become indispensable. The revision formula uses the indices published by INSEE and is calculated according to the contractual formula agreed at signature.
Whole-life analysis: reasoning over the life of the building
A material that costs more to install can prove cheaper over the life of the building, 30 to 50 years, once maintenance, replacement and running costs are taken in.
| Triple against double glazing | An initial premium of 15–25 %. Energy savings of 10–20 % on heating according to the climate zone. Payback in 10–15 years at current energy prices. |
|---|---|
| Fibre cement cladding against render | An initial premium of 20–40 %. Saves one redecoration, 20–40 k€ on a medium-sized building, every 20–30 years. A very favourable balance over 50 years. |
| A high-performance heat pump against a gas boiler | An initial premium of 20–40 % according to capacity. Running cost savings of 30–60 % on the energy bill, reinforced by the environmental regulations. |
| Textured render against mineral paint | Double the initial cost. Three times the life, 15–20 years against 5–8. A net saving on the second maintenance cycle. |
Related articles: How to estimate the cost of a project · cost per square metre by building type · Expenditure items on a construction site · Construction costs and estimates
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The cost indices mentioned come from the national statistics and sector publications for France. The waste factors come from professional practice, source: Widloecher and Cusant, Manuel de l'étude de prix, 5th ed.
ℹ The nature of the figures The orders of magnitude on this page are expressed as percentages of a total, not as amounts. They therefore do not drift with the building cost index and need no updating: it is the distribution that is the reference, not the level. The amounts those percentages apply to must be taken at the date of the study. To bring them forward, use the BT01 all-trades index published monthly by INSEE on its 2010 base, which stood at 134.7 in January 2026.
The nature of the figures quoted
The percentages and amounts quoted on this page are orders of magnitude for framing, not measurements. They illustrate mechanisms and proportions, and they substitute neither for a tender exercise nor for an estimate prepared on drawings.
Sources: the BT construction cost indices published monthly by INSEE on its 2010 base, used to update the figures · construction cost statistics from SDES, the statistical service of the ministry responsible for construction · regulatory texts published in the Journal officiel and consolidated on Légifrance for the requirements cited.