Structural Calculations for Dormer Loft Conversions
A dormer loft conversion is one of the most popular ways to add extra space and value to your home - but before construction can begin, you’ll need accurate, professional structural calculations.
At Loft Designs, we specialise in structural calculations for dormer loft conversions, helping homeowners, architects, and builders ensure their projects are fully compliant with building regulations and approved by Building Control.
Why Structural Calculations Matter
Every dormer loft conversion involves structural alterations - from removing sections of the existing roof to inserting new steel beams, joists, and supports. These changes affect how loads are distributed through your home, and that’s where structural calculations are essential.
Our structural engineers assess your property’s layout and propose safe, efficient solutions to support your new loft space. Without these calculations, your project risks delays, added costs, or non-compliance with regulations.
Loft Floor Joist & Trimming Joist Calculations
Most ceiling joists and roof truss chords are not designed to support a full domestic floor load. Our loft conversion structural pack includes a new floor design with detailed beam calculations, ensuring your structure can handle the additional weight. It also covers trimmer joists for stair openings and reinforced joists for dormers, partitions, and baths—meeting all building regulation requirements.
Steel Beam Calculations
In most loft conversions, steel beams are essential for supporting new floors and roof modifications. Our calculations ensure correct beam sizing, placement, and load distribution, whether using existing load-bearing walls or steel supports. If a dormer is part of your design, we provide structural ridge beam calculations for optimal support.
Designed to Comply with UK Building Regulations
Our structural calculations are carried out in accordance with current UK building regulations and are accepted by Building Control authorities nationwide. We’ll work with your architect’s drawings or builder’s specifications to ensure a safe, approved design that supports your vision.
Structural Calculations for Loft Conversions, Extensions & New Builds
Loft Conversion Structural Calculations
Our loft conversion structural calculation packages include everything needed for Building Control approval, material ordering, and builder reference. Simply provide architectural plans or a measured survey, and we’ll handle the rest.
Our calculation pack includes:
-
Steel beam calculations for loft extensions and roof support, including padstone/bearing plates, splice calculations, and fabrication details
-
Floor joist calculations, including trimming joists
-
Rafter and roof modification calculations
Structural Calculations for Home Extensions
A home extension is a great way to add space—whether it’s a larger kitchen, additional bedrooms, or an open-plan living area. Our team provides precise structural calculations for extensions, ensuring compliance with Building Control regulations.
We offer:
-
Steel beam calculations for single and double-storey extensions
-
Load-bearing wall assessments and modifications
-
Foundation and floor structure calculations
%20(39).png)
New Build Structural Calculation Packages
For new build dwellings, we offer comprehensive structural calculation packs to support your Building Control approval. All we need is your architectural plans and Phase 2 site investigation report.
Our full new build calculation packages include:
-
Foundation calculations
-
Masonry or timber-framed wall calculations
-
Floor calculations
-
Roof calculations
We deliver reliable solutions for residential loft conversions, attic conversions, home extensions, and internal alterations
Structural Calculations Suitable for Part A Building Regulation Submissions
%20(33).png)
40+
Backed by over 40 years of structural engineering experience
50+
Team members enabling engineering across the UK
1000+
Residential, commercial & industrial projects nationwide
1
quick and easy online structural calculations service
What Our Clients Say
A Fair Price
Always helpful, punctual delivery of designs & at a fair price. A pleasure to be associated with Loft Designs.
Brooks Building Plans
Helpful and Efficient
Loft Designs have been working on my projects for over 8 years, they are extremely helpful and efficient in finding cost effective structural solutions to my architectural projects.
Tony Angeletta Architect
Cannot Fault their Service
I have worked with Loft Designs for a couple of years now and cannot fault their service. They are always happy to help and I look forward to working with them going forward.
Steven C.
This is a very reliable & professional…
This is a very reliable & professional company with excellent service and very prompt in providing assistance !
L.Bin
Loft Designs A+
I have used Loft Designs on many projects and on each time they have delivered both in quality and costs. They always happy to help with any queries. I would highly recommend.
Bobyas
Professional & Knowledgeable
I couldn't be more happy with the service received from Loft Designs. From start to finish, their team was professional, knowledgeable, and attentive to every detail.
Mr. J. Snitzer
Practical, Cost-Effective
Finding a structural engineer who truly understands the needs of our community isn’t easy, but Loft Designs does exactly that. Their experience with local properties and commitment to delivering practical, cost-effective solutions makes them the go-to choice for structural design.
S. Oppenheimer
Smooth & Stress-free
After researching several companies for our loft conversion project, we decided to go with Loft Designs, and we're so glad we did. Their expertise in structural engineering and their solutions made the entire process smooth and stress-free.
M.Reece
Incredibly Easy
Loft Designs made the experience of a loft conversion less stressful. They provided a design which ensured it was structurally sound and compliant with all regulations.
T.Syed
Frequently Asked Questions
Loft Designs is an online service, offering structural calculations for loft conversions across the UK.
*Prices are for guidance only. Final cost depends on the scope of work, site size, and location.