You need a structural engineer’s input for the floor and any steels. An architect is optional for straightforward conversions, though useful for complex layouts or planning applications. We handle the engineering and certification, so you do not need to arrange these separately.
The engineer’s role is the important one. An attic floor was usually built to hold up a ceiling, not to carry people and furniture, so it needs strengthening with new joists and, in many cases, steel beams. The engineer calculates what is required and specifies it, which is what allows the work to be signed off properly at the end with a Certificate of Compliance.
An architect is a different matter. For a standard Velux conversion or a simple layout, you generally do not need one; the design side is well understood and we can handle it. Where an architect earns their fee is on more involved projects: an awkward layout, a larger dormer that changes the look of the house, or a job that needs a planning application, where drawings and design detail carry more weight. Our planning permission page explains when that comes into play.
The practical upshot is that most homeowners do not have to line up a team of professionals themselves. We coordinate the structural engineering and provide the certification as part of the job. If your project is more complex and would benefit from an architect, we will say so honestly rather than leave you to find out later. To talk through what your home needs, book a free assessment.