The challenges for roof design in homebuilding

When it comes to home building design challenges, roof design is usually at the top of the list. Technological advances in finishes, adhesives and many other components mean that geographical conditions do not necessarily determine the roof design as they once did. In the case of residential design, plan layouts are often more varied, the overall height is lower and personal choice, planning constraints and aesthetics come into play. Thus, when looking on residential design drawings, you’ll seldom find flat terraces, so popular on commercial/office buildings though those too can pose several challenges.

Designing the layout of a residential or commercial structure, taking into consideration its roof, is a cumbersome task. Complex areas like the roof require thoughtful architectural design to provide unique solutions for various requirements, which eventually help to avoid costly mistakes yet meet aesthetic and planning guidelines and requirement.

Choosing to commission an architect means that you access all the insight of a team of professionals that have experience of home building and of course roof design. A client will always be in control because in the end there is a gain of flexibility as experts come up various options for the designs and make sure that they provide homebuilder construction drawings which can be used readily by contractors. Roof design does however pose many complex challenges, a few of them stand out.

Design iteration is the first issue that must be well understood. The roof design will always evolve along the lines of evolving residential homes and commercial building structures. Typically, a design choice is taken early on as per the choice of a sloped or a flat roof. Sloped roofs can come with any number of slopes, from having just one slope, to more than one. Single-sloped roofs are mostly chosen when one side of the structure is narrow and the overall layout fits closely into a rectangle shape. Two slopes are used in similar conditions

when the width of the structure is too big and would collect too much rain water/snow. Flat roofs are often the companion of a contemporary architectural style and require a different approach for drainage and insulation. As long as the starting premises don’t change, the roof design will typically be detailed at later stages when it will be fully and accurately shaped in 3D speeding up the design process.

The support structure of the roof is a fundamental component as it is important for ensuring structural integrity for a number of years. There will always be a number of structural solutions and options to build the same sloped design. Some situations call for traditional wood frames, others require the use of glulam, sometimes metal framing works the best, considering the choice of structural system.

Junctions are another challenge in roof designs and are typically detailed in homebuilder construction drawings. There can be many different scenarios with junctions between different materials and surfaces, depending on the way the roof stands in relation to the house walls. Residential design drawings covering junctions ensure that the roof is perfectly sealed for as many years and weather cycles. Proper ventilation should also be ensured. Close attention to junction details can save significant costs on maintenance.

Drainage is an integral part of roof design, often associated with the various roof junction solutions. Drainage, if not considered at the start may end up quite displeasing, aesthetically. When looking for an environmentally-friendly design, drainage can help in harvesting water. Also, when properly designed, drainage keeps the facades clean, avoiding dirt drippings that are sadly a common sight in many places, particularly on terraced roofs. A reliable architect specialising in homebuilding design will have the expertise required to manage the complexity of a drainage system and ensure minimal maintenance efforts to keep it running well.

When considering the design of a highly technical component of a structure, such as roofing, any experience a client might have had in the past, will fall short and enlisting a specialist will save money in the long run as the potential costs of poor roof design are very high.

Ideally, using an architect to design the house and roof detailing is critical, whether this is for a specialist one-off build or for a number of buildings within a site. Of course, in many cases a large homebuilder will have in-house design expertise and architects who choose to work with specialist outsourcing homebuilder design support firms to create virtual 3D models and detailed construction drawings that would be used by site teams and manufacturing teams.

Kuldeep Bwail, Director at XS CAD, providing 3D Architectural Modelling,3D BIM Modeling to Homebuilder, Architect