Portsmouth and Southsea
Portsmouth is one of the most densely built cities in England. Most of the housing stock that drives structural engineering work sits on Portsea Island, where terraced and semi-detached properties are tightly packed, rear plots are compact and the Victorian and Edwardian masonry is now well over a century old. We provide fixed-fee structural calculations for homeowners, builders and small developers across Portsmouth and Southsea, ready for Portsmouth City Council Building Control.
We carry out the majority of residential projects remotely, working from your photos, drawings and dimensions where the work is suitable for that approach. Calculations are delivered by email, signed by a Chartered Structural Engineer and formatted for submission to Building Control.
Portsmouth enquiries answered within one working day.
Every fee is fixed and confirmed in writing before any work begins. No hourly rates, no hidden charges and no surprises on the invoice.
| Service | Typical Fee | What Is Included |
|---|---|---|
| RSJ beam calculation | £245 to £450 | Beam sizing, padstone specification, masonry bearing checks, structural drawing |
| Load bearing wall removal | £300 to £600 | Full Building Control calculation pack, load path analysis, padstone details |
| Chimney breast removal | £350 to £700 | Calculations for each floor affected, stack support where required, drawing |
| Loft conversion structural design | £395 to £1,200 | Floor joists, ridge beam or purlin, dormer framing, padstone and bearing details |
| Rear extension structural package | £600 to £1,500 | Opening beam, foundation specification, roof structural design, connection details |
| Structural report or defect assessment | £350 to £900 | Crack assessment, pre-purchase report, retrospective Building Control assessment |
We cover all common residential structural engineering across Portsmouth city and the wider PO postcode area. Every pack is signed by a Chartered Structural Engineer and ready for Building Control submission.
The ground-floor wall between front and back rooms is load bearing in almost every Victorian and Edwardian terrace in Portsmouth. We size the steel beam, check the masonry bearings, specify the padstones and produce a drawing your builder can follow on site. From £245, Building Control-ready. See our load bearing wall removal guide.
Southsea and Fratton have a high concentration of Victorian and Edwardian properties with traditional cut roofs suited to loft conversion. We design the new floor structure, ridge beam or steel purlin and dormer framing where required. We always check the existing roof before specifying anything. From £395. See our loft conversion structural design guide.
Compact rear plots are common across Portsmouth's terrace stock, but extensions of 3 to 4 metres are still viable and popular as kitchen-diners. We design the opening beam, specify the foundations and produce the structural drawings for Building Control. Party wall proximity is considered throughout. Extension packages from £600. See our extension structural engineering guide.
Portsmouth terraces typically have chimney breasts running through two or three floors. Removing at ground floor while the breast remains above requires a new support beam at first-floor level. We produce separate calculations and drawings for each affected floor. Chimney breast removal calculations from £350.
Wide openings in older Portsmouth terraces carry more load than many homeowners expect, particularly where a staircase or chimney sits above the wall. We size the beam, check the load path and produce the Building Control calculation pack before you order the door. From £245. See our bifold door structural calculations page.
Every pack includes a clear structural drawing formatted for Portsmouth City Council Building Control or your Registered Building Control Approver. We respond to inspector queries at no extra charge and track any additional comments raised during the approval process.
Several factors specific to Portsmouth's built environment affect how structural alterations should be approached. Understanding these before specifying any beam or padstone is part of how we work on every project.
The majority of Portsmouth's Victorian and Edwardian terrace stock sits on Portsea Island, where the city is most densely built. These properties use solid brick internal walls rather than the cavity construction you find in post-war housing. Load bearing walls in solid brick behave differently from cavity walls: padstone sizing, bearing stress distribution and the way the masonry takes concentrated load all need separate consideration.
Most terrace streets in Southsea, Fratton and North End have shared party walls on both sides. A structural alteration that affects the party wall line, even slightly, involves obligations under the Party Wall Act 1996. We do not provide party wall surveying services, but our calculation packs are formatted so that they can be shared directly with your party wall surveyor or included in a schedule of condition.
Rear gardens on Portsea Island terraces are often short: 6 to 10 metres is common in Fratton, Southsea and Copnor. This affects the structural options for extensions, particularly foundation depth near the boundary and the structural interaction between a new extension and an older rear addition that may already exist.
Retrospective Building Control work is also a frequent enquiry for Portsmouth properties. A significant number of terraced homes in PO1 to PO4 had wall removals and beam installations carried out in the 1980s and 1990s without formal Building Regulation approval. If you are selling and the buyer's solicitor has flagged missing approval documentation, a retrospective structural assessment and calculation pack is often the fastest route to resolving the issue. See our structural engineer report page for more on what this involves.
North of the island, the housing stock changes considerably. Cosham, Portchester and Drayton have inter-war semis from the 1920s and 1930s alongside post-war cavity construction from the 1950s through to the 1970s. Cavity walls carry load differently from solid brick, and floor spans in these properties tend to be longer than in the island terraces. The structural calculations for a wall removal in a Cosham 1950s semi look materially different from the equivalent job in a Southsea Victorian terrace. We treat each property type separately and identify the construction method from photos before confirming any specification.
Havant and Waterlooville have a larger proportion of 1960s, 1970s and 1980s housing: detached and semi-detached properties on estate layouts with cavity brick construction and, in some cases, timber frame elements. These homes have become popular for extensions and loft conversions as families grow and moving becomes more expensive. The structural requirements for these projects are well-established, but the beam sizing, foundation specification and roof alteration details must still be calculated for each individual property. We cover both areas within our standard PO postcode service.
Most Portsmouth enquiries are quoted the same working day. The more detail you provide upfront, the faster we can confirm a fixed fee.
Clear photos from both sides of the wall, the room directly above and any ceiling or floor structure visible. For loft conversions, photos of the existing roof space including rafters, ceiling joists, the ridge and the external eaves.
An estate agent floor plan, an architect's drawing or a hand-drawn sketch showing where the wall sits in the property and where the proposed opening will be. It does not need to be to scale or professionally produced.
The proposed opening width, the approximate age of the property, the construction type if you know it (solid brick, cavity, timber frame) and your PO postcode. The postcode helps us identify any area-specific ground conditions relevant to foundation design.
Whether you are going through Portsmouth City Council Building Control or a Registered Building Control Approver. If you are not sure, we can advise. It makes no difference to our fee, but it affects how we format the calculation pack and drawing.
Recent feedback from homeowners and builders across England and Wales.
"The RSJ calculations arrived the next morning and the drawing was exactly what the Building Control inspector wanted. No queries, no delays. The fixed price made it straightforward to budget."
Homeowner, Victorian terrace wall removal
"We had a chimney breast across two floors in a terrace we had just bought. The engineer checked the stack loading above before issuing anything. Clear calculations, fast turnaround."
Homeowner, chimney breast removal
"Extension structural drawings produced in under a week. The pack included everything our architect needed and the foundation specification was detailed enough for the builder to price accurately."
Homeowner, rear extension
We serve Portsmouth city and the surrounding PO postcode area. All projects are handled remotely from your drawings and photos, so your exact location within the area makes no difference to the fee or timescale.
Common questions from Portsmouth homeowners, builders and conveyancers.
Yes, if the wall is load bearing. Portsmouth City Council Building Control requires structural calculations before approving any load bearing wall removal. The pack must be produced by a qualified structural engineer and must cover the beam size, padstone specification, masonry bearing checks and a structural drawing. Your builder is not permitted to make these decisions. RSJ calculations for Portsmouth properties start from £245. For more detail, see our guide to Building Regulations for wall removals.
Yes. Our calculations are prepared by Chartered Structural Engineers and formatted for Portsmouth City Council Building Control and for Registered Building Control Approvers. We also answer any queries raised by the inspector at no extra charge. Most RSJ calculations for Portsmouth residential jobs are ready within 24 to 72 hours of receiving your photos and dimensions.
Yes, for most residential projects. We work from photos, drawings and dimensions without needing to attend site. This approach keeps costs down and turnaround fast, and it works well for the majority of wall removals, loft conversions and extensions across Portsmouth. If a project is unusually complex and a site visit would genuinely add value, we say so upfront and include it in the fixed quote.
Fees for Portsmouth residential structural projects range from £245 for a single RSJ beam calculation to £1,500 for a full extension structural package. Load bearing wall removal calculations are £300 to £600. Loft conversion structural design is £395 to £1,200. Chimney breast removal calculations start from £350. All fees are fixed and confirmed before we start. See our full structural engineer cost guide for a complete breakdown.
For most Portsmouth projects we need photos of the wall or structure, a rough floor plan or estate agent layout, the proposed opening width or project description and your PO postcode. Formal architect drawings are useful but not required in order to receive a quote. We will tell you exactly what we need when you make first contact and will not start any chargeable work until the scope and fee are agreed.
Yes. We cover Portsmouth city, Southsea, Fratton, North End, Hilsea, Copnor, Milton, Cosham, Drayton, Portchester, Havant, Waterlooville, Fareham, Gosport and Emsworth. Because we work remotely, your location within the PO postcode area makes no difference to the fee or turnaround time. For projects further afield, send us your postcode and we will confirm whether we can help.
Send your project details and we will come back with a fixed fee by the next working day. We are engineers, not salespeople.
Fixed fees, clear drawings and Building Control-ready calculations for Portsmouth and Southsea. Call 07359 267907 or use the quote form above and we will respond the same working day.
