Extension & loft conversion (Whetstone, North London)
The structural calculations behind this project, prepared by our engineers for building control.
Project Overview
Location
Whetstone, North London
Project Type
Extension & loft conversion
Structural Services
Detailed Calculations
Compliance
Building Regulations
Single Storey Extension & Loft Conversion – Whetstone, North London
This Whetstone home has been completely reimagined with a full property re-modelling, featuring a single-storey rear extension and a loft conversion. Designed to maximise space, natural light, and modern functionality, this project created open-plan living areas on the ground and first floors, along with additional habitable space in the newly converted loft.
To ensure structural integrity, stability, and full compliance with Building Control, PorthouseDean provided expert structural calculations, supporting the RSJ beam installations, load-bearing wall modifications, and foundation reinforcements. This transformation was successfully designed in partnership with Detailed Planning architects, who utilised bi-fold doors and a large rooflight to flood the space with natural light.
Maximising Space & Natural Light with Smart Structural Design
This project included:
✅ A single-storey rear extension – Expanding the kitchen and living area for modern family living
✅ A loft conversion – Creating additional bedrooms and usable living space
✅ Structural steelwork & RSJs – Supporting wide-span openings for an open-plan effect
✅ Bi-fold doors & large rooflight – Maximising natural light and garden connectivity
What we did
Our contributions included:
✔ Structural calculations for the extension & loft conversion – Ensuring safety and compliance
✔ RSJ beam & steel design – Supporting large-span openings and load distribution
✔ Load-bearing wall assessments – Safely modifying existing structures
✔ Foundation analysis – Providing stability for the extended and converted footprint
With expert structural engineering, this Whetstone home now benefits from a bright, modern, and highly functional layout, perfect for family life, entertaining, and future-proofed living.
Thinking About a Home Extension or Loft Conversion? Let’s Make It Happen!
At PorthouseDean, we provide expert structural calculations for home extensions, loft conversions, RSJs, and open-plan renovations.
📍 Providing structural engineering across Whetstone, Barnet, and North London.
Why Extend Your Home?
More Space, More Possibilities
Create an open-plan kitchen, a family hub, or a bright entertaining space.
A Date You Can Plan Around
You choose the delivery date, and the price follows the date.
More Natural Light
A wider opening to the garden needs a beam sized for the load above it. The calculations set that size.
Personalised Design
Every house is built differently. The calculations work from your drawings and the structure you already have.
How PorthouseDean Supports Your Project
Every project is different, but the need for precise, reliable structural calculations remains the same. Our engineers work with:
Homeowners
Ensuring designs are safe, cost-effective, and practical.
Architects
Providing calculations that allow for creative yet compliant designs.
Builders
Making sure construction runs smoothly with clear, reliable specifications.
Planning Your Own Project?
More than 9,000 projects since 2012 have run through the same process. You get a fixed price before you commit, and you choose the delivery date.
📩 Get a QuoteStructural Engineering Services We Offer
Structural Calculations for Loft Conversions
Calculations for the floor, beams and roof changes a loft conversion needs.
Structural Calculations for Wall Knock-Throughs
Beam and support calculations for taking out a wall.
Structural Calculations for Extensions & New Builds
Calculations for foundations, walls, beams and roofs on extensions and new builds.
Structural Calculations for Bi-Fold Doors & RSJs
Beam and padstone sizes for wide openings and bi-fold doors.
Structural Drawings & Building Control Calculations
Complete documentation to help you achieve smooth Building Control approvals.