Structural engineering for two-storey extensions in the Highlands, Moray and Islands

The Highlands, Moray and Islands at a glance

Nation: Scotland
Price region: Scotland
Postcode areas: AB, HS, IV, KW, PH, ZE
Towns covered: 21 listed below, plus surrounding villages
Site visits: Free on the mainland; island and remote addresses by arrangement, with travel costs agreed first

What a structural design involves

This service suits every two-storey extension, because each one needs foundations sized for two storeys and usually steel beams where walls are removed. You get a structural engineer's calculations and drawings for beams, padstones, lintels, foundations and connections, coordinated with the architectural drawings, submitted for building standards and followed through on site by our build teams.

Across Highlands, Moray and Islands we cover Inverness (IV1), Elgin (IV30), Fort William (PH33), Nairn (IV12), Forres (IV36) and Buckie (AB56), plus the smaller places around them.

Fees

A structural engineer (calculations and beam design) is a guide of £750–£2,200, priced in writing once the design is known.

Rules in Scotland

In Scotland, structural calculations form part of the building warrant application, assessed against the Scottish Building Standards Technical Handbooks rather than Approved Documents. The council's building standards service must grant the warrant before any structural work starts, and a completion certificate is submitted when the work is finished.

Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.

Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.

There is no Party Wall Act in Scotland. Shared walls and boundaries are governed by title deeds and common law, so we speak to neighbours early and record the condition of shared structures.

Getting the design right

Tying into the house

The new walls and floors are tied into the existing house with wall ties, restraint straps and joist hangers. The engineer also considers movement between the old and new foundations and where a movement joint may be needed.

Foundations for two storeys

Two storeys put more load on the ground than one, so foundations are usually deeper or wider. Clay soil, nearby trees, drains and made-up ground can all mean deeper trench fill or piles, which is why we dig trial holes before fixing the design.

How we work in the Highlands, Moray and Islands

Visit and first ideas
One of our team visits your house in the Highlands, Moray and Islands, checks the walls, roof and drains, and sketches out options with you.
Get it approved
Once you're happy with the design we submit it to the council for the Highlands, Moray and Islands and deal with any questions from the planning officer.
Technical design
We prepare the building warrant drawings, structural calculations and specification so the build price can be fixed.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Towns we cover in the Highlands, Moray and Islands

Structural engineering for two-storey extensions in the Highlands, Moray and Islands: questions

Will the engineer visit the site during the build?

Not usually at every stage. Building standards inspects the foundations, steelwork and other key stages against the approved calculations. The engineer is called back if site conditions differ from the design, such as unexpected ground, hidden beams or weak existing walls, and issues revised details before that part of the work continues.

How deep do foundations need to be for a two-storey extension?

There is no single depth. It depends on the soil, nearby trees, drains and the loads. On firm ground foundations may be around a metre deep, while clay near trees can need much deeper trench fill or piles. Trial holes and the engineer's design set the depth, and building standards inspects the trenches.

Can a steel beam be hidden in the ceiling?

Often, yes. A beam can sit within the floor depth so the ceiling is flat, but that may mean a deeper steel section or a different floor structure. Otherwise it shows as a downstand below the ceiling. We discuss the options with you and the engineer before the design is fixed.

Neighbouring areas

All extension services in the Highlands, Moray and Islands · About structural engineering for two-storey extensions