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

Massing studies — housing forms built from the Elsi system

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.

Elsi ring beam foundation system
Open spansUp to 3.0 m clear span between supports — flexible ground-floor layouts above the foundation.
Three pile typesScrew, percussion and concrete piles — 95% of UK ground conditions covered by one system.
No muck-awayPiles displace ground rather than excavate it — no spoil to cart away, no surprise groundworks costs, and well-proven around tree roots.

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.

Left-hand wall panelMiddle wall panel with window openingRight-hand wall panel
Pre-cast ring beam and pile foundation

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.

06Performance

Low energy,
by design

Five steps to zero, or negative home energy bills.

  1. 1

    Thermal envelope

    Fabric-first insulation — 0.13 W/m²K walls, thermal bridges designed out before manufacture.

  2. 2

    Airtight envelope

    ≤1.0 m³/h·m² tested airtightness keeps the heat you've paid for inside the building.

  3. 3

    Windows & doors

    Double-sealed, Passive House certified units from our own joinery — fitted and sealed by one team.

  4. 4

    MVHR

    Mechanical ventilation with heat recovery — continuous fresh air without throwing the warmth away.

  5. 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.

1Insulated Beam and Block FloorThermally broken — continuous with the wall insulation line.
2Service voidAll services routed within the service void, preventing penetrations into the building envelope.
3Internal insulated liningActs as airtightness, vapour control and additional thermal lining. Continuous with floor insulation.
4Timber wallFilled with mineral wool insulation — 0.13 W/m²K
5Pre-cast ring beam & pile foundationFaced with thermal break insulation, limiting ground to structure heat transfer.
6FaçadeSupported from ring beam. Fully vented and breathable cavity.
Construction cross-section — wall, insulation and foundation junction detail

07Joinery

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.

Tilt & turn

European-style operation — secure night ventilation, full inward opening for cleaning and egress.

Timber or alu-clad

Engineered timber frames, with an optional low-maintenance aluminium-clad exterior.

Any colour

Factory-sprayed to any RAL colour — arrives on site finished, no decorator required.

Passive House certified

Certified triple-glazed units available for low-energy and Passivhaus projects.

Order up front

Sized from the manufacturing model, so they can be ordered at frame sign-off — no waiting for formed openings.

08Specification

Technical

Every Elsi build ships with a complete documentation set — structural calculations, SAP inputs, and as-manufactured drawings.

Request full specification

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)

09Questions

Frequently
asked

More questions? Reach out

Send us your drawings and we'll return a fixed-price proposal within five working days. Because panels are priced from the manufacturing model — not a quantity surveyor's allowance — the figure you sign is the figure you pay.

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.

10Client 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 portal

Programme

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

11Contact

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

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