Kilton Barns, Somerset
Barn conversion — views over the Severn Estuary
Elsi Design LtdPrecision Timber Frame Homes
Build
Better.
Elsi design, build and supply a complete, integrated system for building low energy timber frame housing. From foundations to turning the key in the door.
21 daysto weathertightZerobill homesArchitectled design
Elsi Design LtdPrecision Timber Frame Homes
Build Better.
Elsi design, build and supply a complete, integrated system for building low energy timber frame housing. From foundations to turning the key in the door.
21 daysto weathertightZerobill homesArchitectled design
01Envelope
One frame, any façade
A facade projects aesthetic quality and personal style. The Elsi system carries a wide range of finishes — from the vernacular to the ultra-modern — all hung from the same superstructure.
TMB-01
Larch cladding
UK-grown vertical board, pre-treated. Warm grain that weathers naturally to silver-grey.
01 / 04
02Architectural Freedom
Works brilliantly with architects — practically and stylistically.
It starts with your architect’s concept design (RIBA Stage 3). We take it forward in parallel — detailed design, building regulations and technical design (Stages 4–5) — and return a realistic price and programme for a fully-formed building.
The Elsi package is everything: foundations, frame, facade, windows, doors and a complementary energy system, engineered as one. From a back-garden development to a whole terrace.
03Foundations
Frame-ready in a week
1
Survey & engineer
Ground conditions assessed; pile layout engineered from your drawings.
2
Piles installed
Screw, percussion or concrete piles — no excavation, no spoil.
3
Ring beam set
Pre-cast insulated beam craned onto the piles, millimetre-accurate.
4
Frame-ready
Typically under a week — the superstructure starts immediately.
04The panel
Panel
by panel
Every wall panel is sized to be lifted and placed by hand — no crane, no heavy plant. It makes the system ideal for sites with limited access, as well as self-builders and extensions.
05Who it’s for
For small developers,
self builders
& architects.
Fixed price
One figure for foundations and frame, specific to your site and ground survey — the price you sign is the price you pay.
One contract
Substructure and superstructure from a single team, with one point of responsibility.
Speed
Weathertight in weeks — internal trades mobilise sooner, scaffold drops earlier, landscaping starts before you'd expect.
Multiple dwellings
The learning curve means speed of construction can be increased whilst maintaining accuracy and using only a small team.
06Projects
Projects
Homeleigh, Devon
New build — complete Elsi turnkey
Housing Forum Terrace
Joint development — affordable terrace
King John Farm, Hampshire
New build — affordable timber frame
Education
Early years day nursery
07Performance
Low energy,
by design
Five steps to zero, or negative home energy bills.
1
Thermal envelope
Fabric-first insulation — 0.13 W/m²K walls, thermal bridges designed out before manufacture.
2
Airtight envelope
≤1.0 m³/h·m² tested airtightness keeps the heat you've paid for inside the building.
3
Windows & doors
Double-sealed, Passive House certified units from our own joinery — fitted and sealed by one team.
4
MVHR
Mechanical ventilation with heat recovery — continuous fresh air without throwing the warmth away.
5
PV + battery
Generate, store and offset. The step that can take your bills past zero.
£0*
*or below. We can’t promise negative bills — every household is different. But take our advice on fabric, systems and solar, and generation can outpace consumption.
08Joinery
Windows & doors,
made in-house
Windows and doors, made by experts. Our Lignum™ range is assembled in our own factory — high performance, Passive House certified, triple glazed. Warmth stays in; light pours through.
09Specification
Technical
Every Elsi build ships with a complete documentation set — structural calculations, SAP inputs, and as-manufactured drawings.
Request full specificationMaterial
Internal liningPlasterboard, Fermacell or FR timber board
InsulationRW45 Rockwool & PIR rigid
External finishesNon load bearing facade. Suitable for brick, brickslip, stone, tile, timber cladding or rendered.
Windows & doorsLignum™ timber or aluminium-clad tilt & turn, manufactured in-house. Factory-sprayed to any RAL colour; Passive House certified units available.
Vapour controlIntelligent hydro-variable vapour control membrane
CertificationUK / EU sourced, FSC or PEFC certified sustainably sourced timber
Timber gradeC24 & C16 graded structural timber / OSB3 sheating / Timber I-joists (BS EN 14081)
Internal lining
Plasterboard, Fermacell or FR timber board
Insulation
RW45 Rockwool & PIR rigid
External finishes
Non load bearing facade. Suitable for brick, brickslip, stone, tile, timber cladding or rendered.
Windows & doors
Lignum™ timber or aluminium-clad tilt & turn, manufactured in-house. Factory-sprayed to any RAL colour; Passive House certified units available.
Vapour control
Intelligent hydro-variable vapour control membrane
Certification
UK / EU sourced, FSC or PEFC certified sustainably sourced timber
Timber grade
C24 & C16 graded structural timber / OSB3 sheating / Timber I-joists (BS EN 14081)
10Questions
Frequently
asked
More questions? Reach out
Send us your drawings and we'll return an initial estimate. As your design and specification are refined, so is the quote — the figure sharpens as the project develops, arriving at an accurate final cost.
Yes. Most Elsi projects begin from an architect's planning drawings. We re-engineer the design into our panel system, returning manufacturing drawings for sign-off before anything is cut — design intent stays intact, buildability improves.
Foundations, sole plates, closed wall panels, floor cassettes, roof structure and all structural fixings — plus the engineering package: calculations, layouts and erection drawings. What it excludes is just as clearly documented, so there are no scope gaps.
Foundations are typically installed in under a week. A single dwelling superstructure is weathertight within 21 days of the first panel arriving. Multi-unit programmes run continuously, with a fresh plot enclosed every few days.
11Client Portal
Transparency.
Visibility.
Control.
Every drawing, certificate, manual and programme update — in one place, from the moment your project begins. The Elsi client portal gives you complete visibility and management of your build, at every stage.
Access your portalProgramme
Live stage timeline with dates
Drawings & specs
Every issued drawing & spec
Contracts
Agreements and signed contracts
Certificates & O&M
Sign-off docs and manuals
Invoices & billing
Your invoices, in one place
Your project team
The full team, one tap away
12Contact
Get in
touch
Self-builder, architect, developer or home-owner — we want to hear from you. Send drawings if you have them; a postcode and an idea is enough if you don’t.
Emailinfo@elsi.dev
Tel01923 604102
Studio + FactoryRams View, Merryfield Farm
Soames Lane, Alresford
SO24 0HF
Soames Lane, Alresford
SO24 0HF
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