A renovation differs from a new build in one fundamental respect: it is limited by the data of the existing building. Plans made without knowing these limits have to change once work begins.
Survey first, then decide
The first step in a renovation is to take measurements on site and record the existing situation. Where the load-bearing walls are, which routes the services follow and what the floor height is directly determine what can be changed. Decisions made without this survey often turn out to be impossible to implement.
The question of the structural system
Whether a wall you want to remove is load-bearing is the most critical question in a renovation. Non-load-bearing partition walls leave room for manoeuvre, but any intervention in the structural system requires an assessment by the relevant engineering discipline. This is a matter of structural safety that takes precedence over aesthetic preferences.
Drawing up a list of works
The scope of a renovation does not become clear until the works are listed item by item. The list of works defines both the sequence and the scope. Every new task added during the process affects the schedule and budget; this effect can only be measured if there is a list.
When permits are required
Changes that affect the façade, the structural system or the arrangement of independent units may be subject to permission from the relevant authority. In shared buildings such as apartment blocks, the management plan and decisions of the owners also come into play. Once the scope is clear, it should be assessed which permits are required.
Making material decisions early
One of the things that slows renovations down most is material decisions not yet having been made when the relevant work is due. Making choices in advance makes delivery times plannable and prevents waiting on site.
Will the space remain in use?
Whether the space will continue to be used during the renovation directly affects the work schedule. Limited works can be planned in phases, while renovations involving bathrooms, kitchens and services usually make use difficult. Discussing this at the outset reduces surprises during the process.