That's another storey!

DESIGN

Good communication is key to find the best and most economical design for your attic rooms.

The planning & design phase is most important, as decisions cannot be left until the building work is in progress.

This is why we come out to your site to plan your roof alterations with you. The position and orientation of your stairs, for instance, cannot be left until last as the whole top floor must be planned around it. We prefer to discuss and design the loft layout first, and then forward our loft design to the architect to incorporate into the plan.

The structural design of your loft room is done on industry leading roof design software which conforms to the SA National Standards. All trusses will be provided by a licensed MiTek roof truss fabricator. All roofs will thus conform to the structural requirements: The Structural Use of Timber (SANS 10163), and: The General Procedures and Loadings to be adopted in the Design of Buildings (SANS 10160).

A roof inspection will be done by a professional engineer on the structural part of the roof and the roof certificate will be handed to you upon completion of the work.

Please also note that not all roofs are suited to be converted to loft rooms. Some roof pitches are too low to create a live-able space, and in other cases the span of the building might be too small to fit a decent sized loft room into.

In these cases the options would be to either build a small loft room for storage, or replace the roof with a totally new attic roof which will be higher than the old roof, or to do a vertical extension (second storey) in timber.

Roof shapes for loft design

The preferred roof-end shape for attic rooms is the gable wall, as it maximizes the attic space and big windows can be built into them to allow lots of light and fresh air into the attic rooms.

Gable to Gable Roof

Gable to Gable Framing

Hip areas are not preferred for attic space, as the hip system of trusses is very complex and cannot easily and economically be converted to a room. If the hip area must be used, please keep in mind that this area will be more complicated and more expensive to convert to a loft room. The best place for the attic space in a hipped roof is from where the horizontal ridge starts to where it ends, as this gives you the more straight forward and economical space.

Hip to Hip Roof

Hip to Hip Framing

In some cases louvre openings can be built into the hip area, which will extend the horizontal ridge line and thus the loft size in length, and create triangular openings where windows can be fitted into.

Louvre Hip

Louvre Hip Window

Ultimately nothing is impossible, and you can even have Polynesian shaped attic trusses ending in Louvre hips. See picture below of a design I did for a house in River’s Edge, Bonnievale.

Polynesian, Louvre Hip, Attic Roof

Polynesian Shaped Attic Truss

Attic size

The Building Regulations recommend a minimum height of 2.4m for a minimum of 6m2 of the horizontal part of the ceiling for habitable attic rooms such as bedrooms, living rooms, kitchens, etc. The average ceiling height of these rooms must be a minimum of 2,1m. For bathrooms, storerooms, etc. the minimum average height is 1,8m. The width of the usable attic space can normally be taken as ⅔ of the building span, but this can vary due to a number of reasons, e.g. roof pitch, roof covering, dormer positions, internal support, etc.

DESIGN

Roof shapes for loft design

Attic size

Attic room - minimum heights for walls and ceiling