South East & East England - 0208 183 4321
South West, Wales & Midlands - 01452 346 156
North England & Scotland - 0161 820 3230
Structural Engineers in Southampton
Residential structural engineering that doesn't leave you guessing
Top-rated structural calculations for residential builds in Southampton. Contact PorthouseDean Structural Engineers today to get your calculations sorted.
We know Southampton's housing stock and what Southampton City Council expects
Offices in Manchester, London and Gloucester, with engineers around the country for site visits. We've worked extensively across Hampshire and know Southampton well — the Georgian → modern Brick terraces, flats, the party wall situations that come with them.
More importantly, we know how Southampton City Council’s building control team operates and we write our calculations to match. That saves time on site and avoids queries coming back.
Local knowledge
PorthouseDean provides structural engineering for extensions, knock-throughs, loft conversions, and two-storey extensions in Southampton. With 120+ calculations completed across Hampshire, our engineers understand the area's Georgian → modern Brick terraces, flats properties, ensuring every design accounts for local building characteristics and Alluvial clay ground conditions. Our most recent project in the area was a loft conversion completed in Jan 2026.
Houses are all we do. That specialism matters when something goes awkward.
We don't do commercial. We don't do bridges. We do extensions, loft conversions, knockthroughs, new builds — and we've done over 120+ of them with a 100% building control success record.
That specialism means when your project throws up something unexpected — and they always do — we've seen it before. We know what works, what building control will push back on, and what your builder actually needs on the page to build from.
The quote's the easy part. It's three weeks later that matters.
The difference between structural engineers doesn't show up in a quote. It shows up when your builder's on site and something doesn't add up. When building control come back with a query. When the design changes halfway through and someone needs new calcs yesterday.
Our calculations are detailed enough that your builder can work from them without ringing anyone. When BC come back with a query, we deal with it — as many as they want. If they want something changed, we change it.
Project changes? Every quote includes a free amendment because we know designs evolve. Need to speak to your engineer? We give you a direct booking link for meetings, and our tech support team handles urgent queries whenever you need them.
A builder standing around waiting for a structural answer costs real money. We're the engineers who pick up the phone.
Fixed fee. No surprises after you've committed.
The number we quote is the number you pay. No extras bolted on for BC queries, no awkward invoice three months later.
Recent Projects Near Southampton
Loft conversion
Other
Two-storey extension
Bespoke / specific calcs
Single storey extension
Send plans. Get a quote. We handle the rest.
Send us your plans
Fixed fee quote within 24 hours. No obligation, no chasing.
What people say
Other Areas in Hampshire
Frequently Asked
If you're removing a wall, converting a loft, building an extension, or doing anything that affects the structure of your house — yes. Building control will require structural calculations before they sign off the work.
A virtual site visit is included in every quote — it's a chance to put a face to the name and talk through specific design requirements with your engineer. But we don't believe a physical visit is necessary for most residential projects. Working remotely allows us to be more economical while maintaining the same quality throughout. If your project does need a physical visit, we have engineers around the country who can arrange one.
Quote within 24 hours of receiving your plans — often much quicker. Standard delivery is 10 working days, but we can turn calculations around in as little as 1 working day if you need them urgently.
Having completed 120+ projects across Hampshire, we can confirm structural calculations typically start from £500 + VAT.
Fees depend on the scope and complexity of your project. We provide clear, fixed-fee quotes within 24 hours so you know exactly what you'll pay before we start. No hidden costs, no extras for building control queries.
Every quote includes one free amendment because we know projects change — that's normal. Beyond that, we'll quote any further changes clearly so there are no surprises.
The quote's not the product — the project is. A cheaper set of calculations might get you through the door, but when building control query something or your builder can't follow the drawings, that's when it costs you. We include BC queries, an amendment, and a virtual site visit because that's where projects actually succeed or fail.
Local Area Information
Understanding Southampton's unique characteristics helps us deliver precise structural solutions.
About Our Southampton Structural Engineering Services
Professional Structural Calculations for Hampshire Properties
Your project deserves engineers who know Hampshire inside and out. We work extensively with the area’s building heritage – Georgian → modern constructions using Brick terraces, flats. Our familiarity with Southampton City Council processes means faster approvals and fewer complications for your project.
Structural Calculations Tailored to Hampshire Properties
Every area has its challenges. In Hampshire, we regularly work with Alluvial clay, which requires specific foundation design approaches. Alluvium over London Clay Our structural engineers account for these local conditions in every calculation, ensuring your extension, loft conversion, or structural alteration is built on solid foundations.
Experience Across Hampshire’s Property Types
From Victorian terraces; modern apartments, we’ve handled projects throughout Hampshire. Whether your property sits near Titanic Trail; Southampton Docks or benefits from proximity to South Western Main Line; M27, we understand the local context.
Our established relationship with Southampton City Council building control helps expedite your project. We consistently deliver calculations that meet their standards, minimising delays and resubmissions.
Coverage Across Hampshire
Operating throughout Hampshire and surrounding areas (population: 260 k), our services include:
• Loft conversion and roof extension calculations
• Extension designs – all configurations
• Internal structural alterations
• Steel beam and RSJ specifications
• Foundation and underpinning calculations
Structural Calculations Quote for Your Hampshire Project
Ready to move forward? Contact PorthouseDean for structural engineering services in Hampshire. We provide clear, competitive quotes within one business day.
Ready to get started?
Send us your plans for a fixed-fee quote within 24 hours. Or call us — we actually answer.
