Description
Near-Passive House thickness for Energiesprong, net-zero new-build, and Social Housing Decarbonisation Fund band A pathways — 180 mm graphite EPS at λD 0.031 W/mK delivers RD 5.80 m²K/W, the depth that drops typical UK masonry walls to 0.15–0.17 W/m²K and reaches the Passive House wall threshold on well-pointed brickwork. Three boards per pack, 1.5 m² coverage, dispatched next working day from our Southampton warehouse.
What EPS Grafit 180 mm Does in a UK EWI System
The Genderka EPS 031 Fasada Extra Plus 180 mm is a graphite-enhanced expanded polystyrene insulation board with declared thermal conductivity λD 0.031 W/mK and thermal resistance RD 5.80 m²K/W. Certified to EN 13163, it serves as the primary insulation layer in high-performance EWI systems on Passive House, Energiesprong, and net-zero projects up to 18 m in height. It sits within the wider graphite EPS insulation board range as the near-Passive thickness — the depth at which standard UK masonry walls reach 0.15–0.17 W/m²K, approaching the ≤ 0.15 W/m²K wall fabric target used in Passive House energy-balance calculations.
Specifiers reach for 180 mm when the project targets Passive House pre-certification, net-zero operational carbon, or Social Housing Decarbonisation Fund band A pathways. The 0.65 m²K/W gain over 160 mm crosses the line between deep-renovation performance and certified Passive House territory on well-pointed brickwork, while staying within standard masonry-construction build-up depths and planning-consent proportions.
Why Specifiers Choose EPS Grafit 180 mm for UK Walls
- Passive House wall threshold on well-pointed brickwork — assembly U-value lands at 0.15–0.17 W/m²K on standard 215 mm solid brick, touching the ≤ 0.15 W/m²K Passive House target where brick conductivity is at the lower end of the typical range.
- RD 5.80 m²K/W from a 180 mm depth — graphite bead chemistry matches roughly 225 mm of white EPS, saving over 45 mm of total build-up depth and protecting architectural proportions on net-zero new-build elevations.
- Energiesprong-compatible performance — the consistent λD 0.031 W/mK across the production range underpins reliable U-value calculations at scale for guaranteed-performance whole-house retrofit contracts.
- Social Housing Decarbonisation Fund band A enabler — combined with high-performance glazing, loft insulation, and MVHR, the 180 mm wall element delivers the fabric performance needed for the most ambitious band D-to-A upgrade pathways.
- Self-supporting board rigidity at depth — BS100 bending strength keeps the board flat when leant against the wall face, no bowing or deflection during the 24-hour adhesive cure window.
- Standardised installation across the EWI range — bonds with the same adhesives, basecoats, and meshes as thinner variants; only the fixing plug length steps up to the LTX 220 mm — the longest plug in the standard LTX range.
- Direct from Southampton warehouse — pallet quantities for Passive House and net-zero programmes typically dispatched next working day, with consolidated EWI system orders shipped on a single delivery.
Thermal Specifications — λ, U-Value, Reaction to Fire
| Property | Value |
|---|---|
| Declared thermal conductivity (λD) | 0.031 W/mK |
| Thermal resistance (RD) at 180 mm | 5.80 m²K/W |
| Indicative wall U-value (215 mm solid brick + 180 mm) | 0.15–0.17 W/m²K, subject to calculation |
| Reaction to fire (EN 13501-1) | Euroclass E |
| Classification string | EPS EN 13163 T1-L2-W2-Sb2-P5-BS100-DS(N)2-DS(70,-)2-TR100 |
Under current Approved Document B guidance, Euroclass E EPS is permitted within EWI build-ups on residential buildings below 18 m where the project fire strategy specifies horizontal mineral wool fire barriers at each floor level and around openings. For buildings above 18 m or where the project fire strategy requires non-combustible insulation throughout, switch the specification to the mineral wool insulation range — the trade-offs between graphite EPS and mineral wool at enhanced thicknesses are set out in the graphite EPS vs mineral wool 2026 facade guide.
Physical Specifications — Density, Strength, Dimensions
| Property | Value |
|---|---|
| Manufacturer | Genderka Sp. z o.o. |
| Range | EPS 031 Fasada Extra Plus |
| Thickness | 180 mm |
| Board size | 1000 mm × 500 mm |
| Coverage per board | 0.50 m² |
| Boards per pack | 3 |
| Pack coverage | 1.5 m² |
| Density | 15 kg/m³ |
| Bending strength | ≥ 100 kPa (BS100) |
| Tensile strength perpendicular to faces | ≥ 100 kPa (TR100) |
| Dimensional stability (normal) | ± 0.2 % (DS(N)2) |
| Standard | EN 13163:2012+A1:2015 |
Where EPS Grafit 180 mm Performs Best — Wall Types and Build-Up
The 180 mm graphite EPS board is the near-Passive thickness for projects where wall-element performance must cross from deep-renovation into certified Passive House territory. Three project types account for the majority of UK use cases at this depth.
Passive House New-Build and Pre-Certification
Projects pursuing Passive House certification reach for 180 mm of graphite EPS as the external wall insulation layer, delivering 0.15–0.17 W/m²K on standard 215 mm brick. On well-pointed brickwork with conductivity at the lower end of the typical range, the wall element alone reaches the ≤ 0.15 W/m²K fabric target without supplementary internal insulation, simplifying the construction sequence and protecting room sizes.
Energiesprong Whole-House Retrofit
UK Energiesprong programmes specifying factory-precision EWI panels favour 180 mm for its combination of substantial R-value and consistent declared λ across the production range. The reliable thermal characteristics underpin the guaranteed-performance contracts that define this delivery model, where calculated U-values must match measured post-installation performance within tight margins.
Net-Zero Carbon New-Build
Developers and architects designing to net-zero operational carbon standards reach for 180 mm to push the heating-demand contribution from external walls to the lowest practical level. The resulting wall U-value frees the dwelling emission rate calculation from compensating heavily through services specification, allowing simpler MVHR and heat-pump sizing.
How EPS Grafit 180 mm Fits Into a Full EWI System
Boards bond to the prepared substrate with a circumferential-and-spot adhesive bead from the EPS adhesives and basecoats range, aiming for a minimum 40 % contact area to satisfy wind-load design under BS EN 1991-1-4. At 180 mm board depth full-face support is critical: maintain a continuous perimeter bead at least 30 mm wide and three central spots each at least 100 mm in diameter to prevent voids that could allow board deflection under negative wind pressure on exposed elevations.
After a minimum 24-hour adhesive cure, secure with 6–8 mechanical fixings per m² from the insulation fixing accessories range. The matching fixing plug for 180 mm boards on standard masonry is the LTX 220 mm polystyrene fixing plug — the longest in the standard LTX range — providing 30–40 mm of embedment beyond the board and adhesive layer. Note that this plug ships in 100-piece packs rather than the 200-piece packs used for shorter variants, so adjust ordering quantities accordingly. Rasp the outer face to create a basecoat key, then apply reinforcing basecoat with embedded fibreglass mesh and finish with the project's specified render system. The full layer-by-layer sequence is mapped in the EWI system build-up layers explained guide, where the dependencies that determine programme length are set out for each stage of the build.
How EPS Grafit 180 mm Compares to Sibling EPS Boards
| Property | 160 mm Grafit (deep renovation) | 180 mm Grafit (this board) | 200 mm Grafit (maximum depth) |
|---|---|---|---|
| Thickness | 160 mm | 180 mm | 200 mm |
| λD | 0.031 W/mK | 0.031 W/mK | 0.031 W/mK |
| RD | 5.15 m²K/W | 5.80 m²K/W | 6.45 m²K/W |
| Indicative U-value (215 mm brick) | 0.17–0.19 W/m²K | 0.15–0.17 W/m²K | 0.13–0.15 W/m²K |
| Pack coverage | 1.5 m² | 1.5 m² | 1.5 m² |
| Matched fixing plug | LTX 200 mm (200-pack) | LTX 220 mm (100-pack) | LTX 220 mm (100-pack) |
| Typical specification | PAS 2035 band A | Near-Passive, Energiesprong | Certified Passive House |
Choose 180 mm when the project targets Passive House pre-certification, net-zero carbon design, or Energiesprong-style guaranteed-performance retrofit. Step down to 160 mm for PAS 2035 band A deep renovation without the Passive House wall-element threshold; step up to 200 mm when the wall U-value must clear 0.15 W/m²K independently regardless of brick conductivity. The calculation method behind these U-value bands sits in the U-value calculation and wall insulation thickness guide.
How EPS Grafit 180 mm Performs in UK Weather — Moisture, Frost, Wind Loads
Graphite EPS has a closed-cell structure with very low water absorption (W2 classification under EN 13163), allowing the board to maintain declared thermal performance through the wet UK heating season when installed within a correctly detailed render or EWI system. Freeze-thaw cycling does not degrade the bead structure, and the material is unaffected by typical UK winter temperatures.
Wind-load resistance at 180 mm depth depends substantially on the combined adhesive and mechanical fixing specification rather than the board itself. On standard UK exposure zones the recommended 6–8 plugs per m², combined with full-perimeter adhesive contact, delivers reliable retention to BS EN 1991-1-4 design pressures. On exposed coastal or upland sites, increase fixing density to 8–10 per m² and verify with the project structural engineer — the LTX 220 mm shank transmits considerably more lever-arm force to the substrate than shorter plugs, so embedment depth and substrate quality matter substantially more than at standard retrofit thicknesses. Condensation risk on solid-wall retrofits at enhanced insulation depths is covered in the dew point and condensation risk guide, where the physics behind thicker insulation actually lowering interstitial risk on most masonry constructions is set out in full.
Handling and Storage on Site
At 180 mm and 15 kg/m³ density each board weighs roughly 1.35 kg, still comfortable for single-handed positioning at scaffold height. At this depth the bulk of each pack and the heat-absorbing graphite face both demand more disciplined site handling than the standard 80–100 mm retrofit thicknesses. The pro-tips below capture the workflow adjustments that pay back across a Passive House or net-zero programme.
- Widen scaffold platforms to 900 mm — standard 600 mm scaffold boards leave limited working space once a 180 mm board is propped against the wall. A 900 mm platform or double-board configuration provides comfortable room for adhesive application and fixing operations.
- Pre-stage full packs per lift in fixing sequence — at 180 mm depth packs occupy substantial platform footprint. Pre-staging from the base track upward minimises repositioning at height and keeps the working area clear for adhesive and fixing tools.
- Rasp and adhere within the same working window — the factory skin on graphite EPS benefits from a mechanical key, and the freshly rasped surface provides the strongest bond. Avoid rasping the full day's allocation in advance because the prepared surface gathers airborne dust.
- Use a depth stop on the drill at 220 mm fixing length — consistent embedment across the full façade is essential at this plug length. Verify embedment on the first few fixings of each elevation before proceeding, and account for the 100-piece pack size when calculating fixing quantities.
Certifications and Compliance — BBA, EN, Reaction to Fire
- EN 13163:2012+A1:2015 — harmonised European standard for factory-made expanded polystyrene products, covering declared thermal conductivity, dimensional tolerances, and mechanical strength properties.
- Reaction to fire — Euroclass E (EN 13501-1) — suitable for EWI systems on residential buildings below 18 m where the project fire strategy specifies horizontal fire barriers at each floor level, under current Approved Document B guidance.
- CE marking and Declaration of Performance — every pack traceable to the originating Genderka facility, supporting Building Control evidence packs, PAS 2035 retrofit coordinator records, and SAP assessor documentation.
- Passive House and net-zero contribution — at RD 5.80 m²K/W the board typically delivers wall U-values of 0.15–0.17 W/m²K on 215 mm solid brick, approaching the ≤ 0.15 W/m²K wall target used in Passive House energy-balance calculations and substantially exceeding all current Approved Document L thresholds. The wider regulatory trajectory is set out in the Future Homes Standard 2026 guide.
All thermal values stated are declared (λD, RD) per EN 13163 and manufacturer technical data sheet (Genderka karta techniczna nr W31FEP, July 2024). Actual installed U-values depend on wall construction, adhesive coverage, fixing thermal bridging, and the complete EWI system build-up. Verify system-level U-value calculations with a competent energy assessor or Building Control body before specifying.
Is EPS Grafit 180 mm Right for Your Project?
- Best fit: Passive House pre-certification, Energiesprong whole-house retrofit, net-zero new-build, or Social Housing Decarbonisation Fund band A pathway on standard masonry constructions.
- Deep-renovation alternative: PAS 2035 band A targets without the Passive House wall-element threshold favour the 160 mm Grafit board at marginally reduced material cost.
- Maximum-depth alternative: certified Passive House projects requiring a definitive ≤ 0.15 W/m²K wall element on any brick type step up to the 200 mm Grafit board at R 6.45 m²K/W.
- Fire-strategy alternative: buildings above 18 m or projects requiring non-combustible insulation throughout — specify from the mineral wool insulation range.
- Bundle route: Passive House and net-zero programmes benefit from sourcing all components through a single EWI system order with consolidated delivery.
What to Order Next — Pack Sizes, Lead Times, Compatible Components
Confirm the surveyed wall area in m², divide by 1.5 m² per pack, and add 5–10 % for cutting waste around reveals, soffits, and service penetrations. Pair each pallet of 180 mm boards with sufficient adhesive and basecoat from the adhesives and basecoats range (typical demand 4–5 kg/m² for the adhesive layer and 4 kg/m² for the basecoat layer), plus the LTX 220 mm fixing plug at 6–8 fixings per m². Remember that the LTX 220 mm ships in 100-piece packs, so a 100 m² façade at 7 fixings per m² requires 7 packs rather than the 4 needed for shorter-plug 200-piece packs.
For Passive House designers, Energiesprong delivery partners, and net-zero programme managers, consolidated take-off sheets, per-m² pricing, and split deliveries phased to scaffold rotation are available on request via the trade desk before the first pallet leaves the warehouse.
FAQ — EPS Grafit 180 mm Thickness, Coverage, Installation
How many packs does a typical detached Passive House new-build require?
A three-bedroom detached new-build with approximately 100–120 m² of external wall area (after deducting windows and doors) requires roughly 70–85 packs of 3 boards, including 5–10 % for cutting waste around reveals, soffits, and service penetrations. For semi-detached or terraced retrofit projects with smaller exposed wall areas, quantities scale proportionally against the measured survey, and the trade desk supports phased delivery for projects with limited on-site storage.
Does 180 mm achieve the Passive House wall U-value target?
On a typical 215 mm solid brick wall, 180 mm of graphite EPS brings the assembly U-value to approximately 0.15–0.17 W/m²K. The Passive House Institute's general target for external walls is ≤ 0.15 W/m²K. On well-pointed brickwork with lower conductivity (≤ 0.70 W/mK), the 180 mm board reaches this threshold on the wall element alone. On higher-conductivity brickwork, the assembly sits marginally above 0.15 W/m²K, which Passive House energy-balance modelling typically accommodates when offset by high-performance glazing, airtightness, and MVHR. For a definitive independent wall-element pass at ≤ 0.15 W/m²K regardless of brick type, the 200 mm board provides the additional margin.
Which fixing plug pairs with the 180 mm board on standard masonry?
The LTX 220 mm polystyrene fixing plug — the longest in the standard LTX range — is the correct match for a 180 mm board on standard brick or block substrates, providing 30–40 mm of embedment beyond the board and adhesive layer. This plug ships in 100-piece packs rather than the 200-piece packs used for shorter variants, so factor the different pack size into ordering calculations. Install 6–8 fixings per m² and use a depth stop on the drill for consistent embedment.
When is 180 mm worth specifying over 160 mm?
The additional 20 mm adds 0.65 m²K/W of thermal resistance and shifts the wall U-value from approximately 0.17–0.19 W/m²K down to 0.15–0.17 W/m²K. For Passive House pre-certification, Energiesprong guaranteed-performance contracts, or net-zero carbon new-build, this margin moves the wall element from deep-renovation performance into certified Passive territory on well-pointed brickwork. For PAS 2035 band A targets without Passive House ambition, the 160 mm board delivers the required performance at marginally lower material cost.
What is the expected service life within an EWI render system?
Within a correctly detailed render system with intact basecoat and finish, graphite EPS maintains its declared thermal performance throughout the EWI system's typical 30+ year design life. Periodic visual inspection of the render surface for impact damage and prompt repair of any breaches preserves long-term insulation performance.
Is the 180 mm board suitable for buildings above 18 m?
For residential buildings above 18 m, current Approved Document B guidance and Building Safety Act 2022 provisions typically call for non-combustible (Euroclass A2-s1,d0 or A1) insulation throughout the façade. Switch the specification to the mineral wool insulation range for these projects, subject to the project fire strategy.