Trusted by Chelmsford homeowners for high-quality structural drawings.
Based in Manchester, with engineers around the country for site visits. We've worked extensively across Essex and know Chelmsford well — the Georgian → modern Brick townhouses, render, the party wall situations that come with them.
More importantly, we know how Chelmsford City Council’s building control team operates and we write our calculations to match. That saves time on site and avoids queries coming back.
PorthouseDean provides structural engineering for extensions, knock-throughs, loft conversions, and two-storey extensions in Chelmsford. With 100+ calculations completed across Essex, our engineers understand the area's Georgian → modern Brick townhouses, render properties, ensuring every design accounts for local building characteristics and River terrace deposits ground conditions. Our most recent project in the area was a single storey extension completed in Nov 2025.
The calculations and drawings are ours. So are the things around them that usually land on you: a date you can plan around, one place where everyone sees the same documents, and the change of mind nobody priced for. More than 9,000 projects since 2012 have run through the same process, from a single wall removal to a whole new build.
Every job runs through the same process, so every customer gets the same three answers.
Tell us about the project and we’ll tell you the price and the steps that follow. No hourly rate. If the job changes, there is a free change request on every job.
Pick how fast you need it, and pay less if you can wait. You get a date to work back from.
Never wonder where it’s up to — just look. Your project hub shows what is happening now, what is next and anything we need from you, with your drawings, documents and invoice alongside. Share it directly with everyone involved in your project.
Building control gets the calculations. Your builder gets the contractor pack. If either of them has a question about the structure, it comes to us, not to you. How we check and what the process looks like.
No extras for building control queries.
A fixed price before you commit. No obligation, no chasing.
It depends on the size and complexity of your project, so we don't publish a price range for Chelmsford. Tell us about your project and you get a clear, fixed-fee quote before you commit.
Sure, we have worked on a wide variety of Chelmsford's Georgian - modern properties. Our engineers aim to understand the specific requirements of your property from Brick townhouses, render construction, ensuring calculations that respect the original structure while meeting modern standards.
Chelmsford typically has River terrace deposits. Alluvium over London Clay. We factor these conditions into our foundation designs, which may affect the depth and type of foundations required.
On a full plans application, Chelmsford City Council has five weeks to decide, or longer if you both agree it in writing (regulation 14A of the Building Regulations 2010). On a building notice there is no plans decision: building control checks the work, and our calculations, as it goes. If they raise a question about the structure, your engineer answers it.
We provide structural calculations throughout Chelmsford and the surrounding Essex area. Our engineers regularly work on projects across the region, and you choose the delivery date that suits you.
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.
On the date you choose when you book. The price follows the date: pick a later one and it costs less, or an earlier one if you need them sooner.
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. The moments that cost you come later: when building control query something, or your builder can't follow the drawings. That's why BC queries, an amendment and a virtual site visit are included — it's where projects actually succeed or fail.
Understanding Chelmsford's unique characteristics helps us deliver precise structural solutions.
Our team brings deep local knowledge to every project. We understand Essex’s unique building heritage – from Georgian → modern properties with their characteristic Brick townhouses, render construction. This expertise matters when calculating loads, designing foundations, and ensuring your project meets Chelmsford City Council building regulations.
Foundation design in Essex requires careful attention to local geology. The area’s River terrace deposits demands specific engineering approaches. Alluvium over London Clay We factor these ground conditions into every design, whether you’re planning an extension, loft conversion, or structural modification.
Comprehensive Knowledge of Essex Properties
Essex’s housing includes Historic terraces; suburban semis, and we’ve worked across this entire spectrum. Your project might be close to Cathedral of Christ; Hylands House or positioned for excellent transport links via Great Eastern Main Line; A130 – either way, we know the area.
Years of working with Chelmsford City Council building control means we understand exactly what they need. Our calculations consistently pass first-time review, keeping your project on schedule.
Coverage Across Essex
Operating throughout Essex and surrounding areas (population: 178 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
Get Started With Your Essex Structural Calculations
Planning your extension or conversion? Reach out to PorthouseDean for structural calculation costs in Essex. You’ll have a clear, fixed-price quote before you commit.
Send us your plans and you'll have a clear, fixed price before you commit. Or give us a call.