- Shell
- External wall insulation
- Wojciech Dobry
- October 2026
- about 8 min
- 3:03, Polish captions
How much EPS for a 100 m² house? Packs with waste
For the walls of a 12 × 9 m single-storey house 3 m high (about 109 m² of facade without windows and doors), buy about 58 packs of 15 cm EPS of 2 m² each, counting 5% waste. On top of that you need about 20 bags of EPS adhesive, 21 bags of base coat adhesive, 3 rolls of mesh and about 700 anchors of 220 mm, but always check the adhesive consumption and the number of anchors in the insulation system's data sheet.
How to calculate it
External wall insulation by the ETICS method (in Poland once called the “light wet” method) is a system: EPS boards glued to the masonry and fixed with anchors, a base coat with mesh embedded in adhesive, primer and a thin-coat render. You work out every material from the same facade area, but with a different waste and consumption.
facade area = external perimeter × height + gables − windows and doors
EPS packs = facade area × (1 + waste) ÷ m² per pack
Measure the height from the starter track (usually above the plinth) to the roof eaves. With a gable roof, add the triangular gables: half the gable's width × its height, times two. The plinth and the foundation wall are usually insulated separately, with extruded polystyrene (XPS), and counted separately.
Deduct the openings by the size of the windows and doors. In exchange, the reveals come in: the strips of wall around the windows (sides and top), which are insulated with thinner EPS, usually 2–3 cm. Their area is the length of the reveals × their depth. Baukit takes the reveal depth as the insulation thickness plus the 5 cm by which the window is set back in the wall: with 15 cm EPS that is 20 cm.
- EPS 15 cm
- reveals 20 cm, thin EPS
- mesh corner beads
- starter track (not across doors)
Packs. A pack of EPS usually holds 0.3 m³, so the number of m² in a pack depends on the thickness: at 15 cm it is 2 m², at 20 cm 1.5 m², at 10 cm 3 m². Check it on the label.
- 10 cm, 3 m² per pack39 packs
- 15 cm, 2 m² per pack58 packs
- 20 cm, 1.5 m² per pack77 packs
The other materials are the facade area times the consumption from the system's data sheet:
| Material | Typical consumption | Pack |
|---|---|---|
| EPS adhesive | 4–5 kg/m² | bag of 25 kg |
| Base coat adhesive | 4–5 kg/m² | bag of 25 kg |
| Glass-fibre mesh | 1.1 m²/m² (10 cm overlaps) | roll of 50 m² |
| Insulation anchors | 4–8 per m², more at the corners | pack of 100 pcs |
| Render primer | about 0.2 l/m² | bucket of 10 l |
| Thin-coat render 1.5 mm | about 2.5 kg/m² | bucket of 25 kg |
The anchor length depends on the EPS thickness: the anchor passes through the EPS and the adhesive and goes into the masonry. Baukit takes a 180 mm anchor for EPS up to 12 cm thick, and for thicker EPS the shortest anchor in the catalogue that is longer than the EPS thickness plus 6 cm for the adhesive and the embedment. At 15 cm that gives a 220 mm anchor, at 20 cm a 260 mm anchor. In walls of blocks with large hollows, the anchor manufacturer may require a deeper embedment.
The starter track runs round the house above the plinth: the perimeter minus the doors. Mesh corner beads go on all the external edges: on the corners of the house and on the edges of the reveals.
Adhesive and mesh are covered in detail in the article how much adhesive and mesh per m² of facade, and anchors in the article how many insulation anchors per m².
Waste
| Material | Waste | Why |
|---|---|---|
| EPS | from 5% to 10% | Cuts at the windows, the corners and under the roof |
| Mesh | about 10% | Overlaps of about 10 cm between strips |
| Adhesives, primer, render | in full packs | The consumption in the system's data sheet already includes typical losses |
| Corner beads, tracks | whole lengths | Each edge is a separate run |
Example: a 12 × 9 m single-storey house
Assumptions: a single-storey house with a hipped roof, external outline 12.00 × 9.00 m, facade 3.00 m from the starter track to the eaves. Six windows of 1.20 × 1.50 m, a front door of 1.00 × 2.10 m, a terrace door of 1.80 × 2.10 m. 15 cm facade EPS (pack of 2 m²), 5% waste. Reveals 20 cm deep (15 cm of EPS and 5 cm). The example in Baukit uses the same data.
- Gross facade. Perimeter 2 × (12.00 + 9.00) = 42.00 m. 42.00 × 3.00 = 126.00 m².
- Openings. 6 × 1.20 × 1.50 + 1.00 × 2.10 + 1.80 × 2.10 = 16.68 m².
- Net facade. 126.00 − 16.68 = 109.32 m².
- EPS. 109.32 × 1.05 = 114.8 m², which is 58 packs of 2 m².
- Reveals. Sides and top: windows 6 × (1.20 + 2 × 1.50) = 25.2 m, doors 5.2 m and 6.0 m, 36.4 m in total. 36.4 × 0.20 = 7.28 m² of thin EPS.
- EPS adhesive. 109.32 × 4.5 = 492 kg, which is 20 bags.
- Mesh. (109.32 + 7.28) × 1.10 = 128.3 m², which is 3 rolls of 50 m².
- Base coat adhesive. 116.6 × 4.5 = 525 kg, which is 21 bags.
- Anchors. 109.32 × 6 = 656 anchors, which is 7 packs of 100. Length: 15 cm of EPS plus 6 cm is more than a 180 mm anchor reaches, so 220 mm anchors.
- Primer and render. Primer: 116.6 × 0.2 = 23.3 l, which is 3 buckets of 10 l. 1.5 mm render: 116.6 × 2.5 = 292 kg, which is 12 buckets of 25 kg.
- Tracks and corner beads. Starter track: 42.00 − 2.80 (doors) = 39.2 m, which is 16 lengths of 2.5 m. Corner beads: 4 × 3.00 = 12 m on the corners of the house and 36.4 m on the reveals, 48.4 m in total, which is 20 lengths of 2.5 m.
- EPS 15 cm58packs of 2 m² (114.8 m²)
- Reveals7.28 m²thin EPS 2–3 cm
- EPS adhesive2025 kg bags (492 kg)
- Mesh3rolls of 50 m² (128.3 m²)
- Base coat adhesive2125 kg bags (525 kg)
- Anchors 220 mm7packs of 100 (656 pcs)
- Render primer310 l buckets (23.3 l)
- Render 1.5 mm1225 kg buckets (292 kg)
- Starter tracks and corner beads16 + 202.5 m each: 39.2 m and 48.4 m
A real house for comparison. The bill of quantities of the free “PS.Arch 150” design from the catalogue of GUNB, the Polish building control authority (a house with an attic storey, 14.15 × 8.44 m), lists 258.25 m² of 20 cm EPS and 16.90 m² of 15 cm EPS, 283.36 m² of mesh and as much as 89.74 m of corner beads. That is almost twice the perimeter of the house (45.18 m), because the corner beads also run round every window and door.
- Net facade
- 109.32 m²
- You buy
- 116.0 m²
- EPS adhesive
- 20 bags
- Anchors (6 per m²)
- 7 × 100
What it costs
| Material | Typical price | ||
|---|---|---|---|
| Facade EPS 70-040 white, 15 cmPack: pack 2 m² (at 15 cm) | 36.94 PLN/m²approx. 74 PLN per packexample: 58 packs, approx. 4,285 PLN34.95–37.90 · 3 shops | 34.95–37.90 | 3 shops |
| Graphite facade EPS 031–033, 15 cmPack: pack 2 m² (at 15 cm) | 41.90 PLN/m²approx. 84 PLN per pack40.97–59.75 · 3 shops | 40.97–59.75 | 3 shops |
| Extruded polystyrene XPS 10 cm (foundations)Pack: pack | 59.67 PLN/m²approx. 134 PLN per pack53.44–77.67 · 3 shops | 53.44–77.67 | 3 shops |
| EPS fixing adhesive, 25 kg bagPack: 25 kg bag | 1.12 PLN/kgapprox. 28 PLN per packexample: 20 packs, approx. 560 PLN0.98–1.16 · 3 shops | 0.98–1.16 | 3 shops |
| Mesh embedding adhesive (base coat), 25 kg bagPack: 25 kg bag | 1.51 PLN/kgapprox. 38 PLN per packexample: 21 packs, approx. 793 PLN1.40–1.57 · 3 shops | 1.40–1.57 | 3 shops |
| Glass-fibre facade mesh 145 g/m², 50 m²Pack: roll 1×50 m | 2.78 PLN/m²approx. 139 PLN per packexample: 3 packs, approx. 417 PLN2.62–4.17 · 3 shops | 2.62–4.17 | 3 shops |
| Insulation fixing (plug) for EPS and wool with steel pin, 10×220 mmPack: pack of 100 | 1.91 PLN/pcapprox. 191 PLN per packexample: 7 packs, approx. 1,337 PLN1.89–1.93 · 2 shops | 1.89–1.93 | 2 shops |
| Primer for thin-coat render, 10 lPack: 10 l bucket (approx. 15 kg) | 17.00 PLN/lapprox. 170 PLN per packexample: 3 packs, approx. 510 PLN12.64–17.40 · 3 shops | 12.64–17.40 | 3 shops |
| Thin-coat silicone render 1.5 mm, 25 kgPack: 25 kg bucket | 7.36 PLN/kgapprox. 184 PLN per packexample: 12 packs, approx. 2,208 PLN6.80–10.76 · 3 shops | 6.80–10.76 | 3 shops |
| Aluminium starter (base) track up to 15 cm, 2.5 mPack: 2.5 m piece (also 2 m) | 10.50 PLN/mapprox. 26 PLN per packexample: 16 packs, approx. 420 PLN8.74–17.16 · 4 shops | 8.74–17.16 | 4 shops |
| PVC corner bead with mesh, 2.5 mPack: 2.5 m piece | 3.96 PLN/mapprox. 10 PLN per packexample: 20 packs, approx. 198 PLN2.44–4.32 · 3 shops | 2.44–4.32 | 3 shops |
| Worked example, total | approx. 10,728 PLN | ||
The “Worked example, total” row is the cost of the materials from the example above: 58 packs of 15 cm EPS, both adhesives, mesh, anchors, primer, render, starter tracks and corner beads, without the thin EPS for the reveals, the XPS for the plinth and the scaffolding.
The prices in the table are the median of offers from several shops, including VAT, dated. Insulation system manufacturers usually require materials from a single system (adhesive, mesh, render) for the system to have a valid technical assessment. So when you compare offers, compare whole systems, not single bags.
Work it out in Baukit
Open in Baukit- Click “Open in Baukit”. A 12 × 9 m single-storey house opens with windows and the notebook open.
- Don't select anything, and leave only the facade in the notebook: you will see the EPS in packs, the adhesives, mesh, anchors, primer and render.
- Change the EPS thickness from 15 to 20 cm in the wall type and see the new number of packs.
- Select one wall to see only its insulation.
- Open the notebook with the “Notebook” button in the bottom left corner or with the 4 key.
The same model also works out the blocks for the walls and the built-up area, which grows with the insulation thickness.
Frequently asked questions
How many packs of EPS for 100 m² of wall?
With 15 cm EPS (2 m² per pack) and 5% waste, it is 105 m², which is 53 packs. With 20 cm (1.5 m² per pack) it is already 70 packs. Always divide by the m² shown on the label for that thickness.
How much EPS adhesive per 1 m²?
Gluing the boards usually takes 4–5 kg of adhesive per square metre, and as much again for the base coat with the mesh. For 100 m² of facade that is about 32–40 bags of 25 kg in total. The insulation system's data sheet gives the exact consumption.
How many insulation anchors per m²?
Usually 4–8 per square metre, and more in the corner zones and on taller buildings. The design or the system data sheet sets the number and layout of the anchors. You choose the anchor length to suit the EPS thickness and the type of masonry: with 15 cm EPS, Baukit counts 220 mm anchors.
Should I deduct windows from the facade area?
Yes, deduct windows and doors. In exchange, add the reveals, which are insulated with thinner EPS, and the mesh corner beads round the openings. In a house with large glazed areas, the openings can be as much as a third of the ground-floor facade.
Which EPS for a facade: white or graphite?
Graphite EPS (λ, the thermal conductivity, about 0.031–0.033) insulates better than white (λ about 0.040), so you reach the same thermal resistance with a thinner layer. You work out the number of packs the same way. Choose the thickness so that the wall meets the Polish building regulations (the technical conditions, WT 2021).
Related
- How much adhesive and mesh per m² of facade? ETICS consumption rates
- How many insulation anchors per m²? Corner zones and wind
4 sources
- Consumption of adhesives, primer and render: data sheets Ceresit CT 85, Atlas Stopter K-20, Baumit DuoContact (adhesive 4–5 kg/m²), Ceresit CT 16 (primer), Ceresit CT 74 and Baumit SilikonTop (1.5 mm render about 2.1–2.5 kg/m²), read on 13 October 2026 (in Polish). Number of anchors: manufacturers do not give it per m²; at least 4 per m², often 6 (Inżynier Budownictwa, in Polish); the design or the system data sheet decides the number.
- Volume of an EPS pack (0.3 m³) and the λ values: EPS manufacturers' data sheets (not checked).
- “PS.Arch 150”, przedmiar robót budowlanych (bill of quantities), author: PS.Arch Piotr Świątkiewicz, 20 November 2023; Główny Urząd Nadzoru Budowlanego, katalog bezpłatnych projektów domów (in Polish), published 15 December 2023 (in the downloads as “Wariant I”): 20 and 15 cm EPS, mesh, corner beads.
- Example: Baukit calculation, 11 October 2026.