Structural engineering for two-storey extensions in Dumfries and Galloway

Dumfries and Galloway at a glance

Nation: Scotland
Price region: Scotland
Postcode areas: DG
Towns covered: 11 listed below, plus surrounding villages
Site visits: Free, no obligation

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.

Towns in Dumfries and Galloway include Dumfries (DG1), Stranraer (DG9), Annan (DG12), Locharbriggs (DG1), Dalbeattie (DG5) and Lockerbie (DG11). If yours isn't listed, we still cover it.

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.

Building on existing structure

When building over a garage or a single-storey extension, the engineer checks the existing footings, walls and lintels. Many were sized for one storey only and need underpinning, strengthening or replacement to carry the new floor.

How we work in Dumfries and Galloway

Measure and listen
A visit to Dumfries and Galloway to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Dumfries and Galloway.
Detail and price
Construction drawings, engineer's calculations and building warrant approval, then a written fixed price for the build.
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 Dumfries and Galloway

Structural engineering for two-storey extensions in Dumfries and Galloway: 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 Dumfries and Galloway · About structural engineering for two-storey extensions