If you’re considering extending your roof space, you’ve probably come across two of the most popular styles: the hip to gable loft UK conversion and the mansard conversion. Both are excellent options for London’s semi-detached and period homes, offering extra space, light and long-term value. But which one is right for your property?
Both designs can dramatically increase your living space and property value, but they each come with their own pros and cons. So which is the best loft extension for semi-detached and terraced homes? Read on to find out how they compare.
What is a hip-to-gable loft conversion?
A hip to gable loft conversion is a clever way to make the most of a hipped roof — the type that slopes on all sides, common in semi-detached and end-of-terrace homes. This design extends the existing “hipped” slope outwards to create a new vertical gable wall, instantly opening up the loft space.
The result is a neater, box-shaped roofline that provides much more usable head height and floor space. For homeowners who feel their loft is too small or cramped for a conversion, this can make all the difference.
Another major benefit is that, in many cases, a hip-to-gable conversion can fall under Permitted Development rights, meaning you may not need full planning permission. (It is still always best to check with your local authority or speak with your loft conversion specialist before starting work.)
What is a mansard loft conversion?
A mansard loft conversion is one of the most spacious and transformative types of loft extension. Named after the 17th-century French architect François Mansart, this design replaces one side of your roof with a near-vertical wall (typically around 72°) and a flat roof on top.
The result? A huge amount of extra living space, almost like adding a whole new storey to your home. Mansard conversions are especially popular for period and terraced properties, where they can blend beautifully with traditional architecture.
However, mansard loft conversion cost considerations can sometimes be off-putting. They can be one of the more complex and costly options, usually requiring planning permission due to the extensive structural changes involved.
Comparing the two: space, style and cost
Space
A mansard conversion gives the most generous internal volume, with full-height ceilings across almost the entire floor. This makes it perfect if you want to create a master suite, several bedrooms, or even a self-contained flat.
By comparison, a hip-to-gable loft provides UK homeowners less overall space, but is still highly practical, particularly when combined with a rear dormer. For many semi-detached properties, this option delivers more than enough room for an extra bedroom, office, or bathroom.
Aesthetics
If you love period details and want your conversion to look like it has always been part of your home, a mansard conversion may be the better choice. The steep rear wall and flat roof can be finished in materials that complement the original façade, giving a cohesive appearance.
Hip-to-gable conversions, on the other hand, retain the traditional semi-detached silhouette, so they blend in well with neighbouring properties while adding modern symmetry to the roofline.
Planning and permissions
In terms of paperwork, hip-to-gable conversions often fall under Permitted Development, whereas Mansards nearly always need formal approval. This can make a difference to both timeframes and budget.
Budget
Because of the greater structural changes and materials involved, mansard loft conversion cost is typically higher than that of a hip-to-gable. However, the extra headroom and resale value can make it a worthwhile investment by boosting value, especially in high-demand areas.
Which is the best loft extension for semi-detached homes?
If you own a semi-detached or end-of-terrace property, a hip to gable loft UK design is often the best fit. It works with the natural shape of your roof, provides excellent value for money, and can usually be completed more quickly than a mansard.
That said, a mansard conversion can also work beautifully for semi-detached homes, particularly when neighbouring properties have undertaken similar projects. Matching the look helps maintain balance and ensures a smooth approval process.
Ultimately, the best loft extension for semi-detached homes depends on your goals. If you want maximum internal space and don’t mind a larger project, a mansard could be ideal. If you prefer a more straightforward build that still delivers great results, hip-to-gable may be the way to go.
Choosing the right attic conversion with Bespoke Lofts
Both hip-to-gable and mansard loft conversions can transform the way you live, adding value, light and functionality to your home. The right choice will come down to your property type, planning flexibility, and how you want to use the new space.
At Bespoke Lofts, we’ll help you weigh up all the options, including hip-to-gable and mansard loft conversion cost, feasibility, and planning implications, before you make any decisions. With over 25 years of experience in creating high-quality, custom-designed loft spaces, we’ll ensure your project runs smoothly from concept to completion.
Ready to discover which loft conversion is right for your home? Get in touch today for expert advice, design inspiration, and a tailored quote for your dream extension.