Flat and Pitched Roof Extensions London

When planning your extension, the roof is an important design element that can impact the look and feel of the overall extension on the outside and on the inside. There are two main roof types here, flat roof or pitched roof and the decision to go for one over the other is not just limited to maximising space and light. Here are some things to consider when choosing between a flat roof extension or a pitched roof extension.

Flat roof extension

A flat roof extension is very common in London. It is a modern extension yet complimentary addition to a Victorian or 1930s style house: particularly the ones typical of London architecture. They are typically single storey extensions and allow you to maximise glazing options. Flat roof extensions are not necessarily cheaper than a pitched roof extension, it depends on the look you are trying to achieve. Generally the bigger costs are in the structural elements of the roof profile. Another element to bear in mind, the thinner or smaller the profile you want (hidden drainage, smaller profile facia and soffits etc) the more it is likely to cost as it becomes “non-standard”.

Benefits of a flat roof extension

By in large, flat roof extensions can be cheaper than a pitched roof alternative. This is typically because of the less structural engineering that is involved and being generally constructed from cheaper materials. That being said, costs do rise when you move away from the standard construction style.

A flat roof extension is also a contemporary addition to your home. It can be nice to mix the old and new and adding a sleek and modern flat roof extension can feel like you are bringing your beautiful Victorian property bang up to date.

A flat roof on an extension is ideal for flooding your extension with light. The flat roof allows for skylights, lightwells and roof lanterns to be installed. This are both aesthetically beautiful design features and important functional elements of a flat roof design providing ventilation as well as light.

Despite their look, flat roofs do have a slight pitch in order for water to run off them. Hidden drainage can also be incorporated to take away the look of chunky drainpipes and gutters giving a sleek and polished finish to the outside.

Downside to a flat roof extension

Over time a flat roof may require more maintenance, and this depends on the material used. In general, the lifespan of a flat roof tends to be shorter than a pitched roof.

As mentioned before a flat roof may not be cheaper than a pitched roof depending on the finished look you want to achieve.

Pitched Roof Extension

There is a wide range of design scope for pitched roof extensions, and it is becoming ever more popular to add more interest and flair to an extension to a period property. It combines the elements of retaining some the period features (pitch) but adding modern touches including skylights, new roofing materials such as zinc and cladding elements.

In terms of the design a pitched extension can follow the traditional slope from the existing wall line, or can be gable ended towards the garden with the roof sloping left and right or what is referred to a North Lights roof. Where there are two slopes in the same direction with a smaller pitch between that can be glazed. It is referred to as a North Lights roof as the glazed sections are typically North facing in order to maximise the light intake but minimise the glaring sun. It was the typical design of industrial units but has been utilised in residential design.

Benefits of a pitched roof Extension

A pitched roof design will generally blend in better with the style of your home, in particular the period properties typical of London architecture. Internally a pitched roof can give you higher ceilings giving great design features internally such as sloped ceilings and exposed beams or steels. Typically, a pitched roof’s lifespan is longer than that of a flat roof due to the more weather resistant materials used externally. Energy wise, a pitched roof can allow for more insulation to be installed then a flat roof.

Downside of a Pitched roof

Pitched roofs can be the more expensive option due to the amount of structural engineering required and the building materials used (tiles as opposed to felt or GRP for a flat roof). Pitched roofs generally take more time to build which usually means a slightly longer build and more labour costs.