The short answer
A penthouse interior is shaped by things you cannot move: the view, the structure, the service risers and the building's rules. Plan around them first, then design the experience. The best penthouses feel effortless because the hard constraints were resolved before the finishes were chosen.
Start from what is fixed
Before any mood board, map what cannot change, and how the space has to work:
- Structure: columns, shear walls and transfer beams, which decide where walls can go.
- Service risers and shafts: where water, drainage and air conditioning enter and leave, which anchors kitchens and bathrooms.
- The facade: window positions, mullions and terrace openings, which belong to the building.
- Ceiling zones: the space above the ceiling that carries ducts and services, which decides finished ceiling heights.
- How the space has to work: who lives there, how each room is used day to day and how the rooms connect, which decides the layout before any finish is chosen.
A layout that ignores these looks good on paper and fails at the first site meeting.
Space planning is where those fixed elements meet the way the owner actually lives. It sets the size and position of every room, the routes between them, where storage and service areas sit, and how private rooms are separated from the spaces used for guests. It is the most important decision in any interior. A beautiful finish cannot rescue a room in the wrong place, too small for its furniture or crossed by the wrong traffic, while a well-planned space feels right before a single material is chosen. That is why we resolve the plan, with furniture drawn to scale, before moving on to mood and materials.
Plan for the view
The view is why most owners buy a penthouse, so the plan should give it to the rooms that use it most. Living and dining spaces usually earn the main frontage; bedrooms often prefer a quieter aspect. Furniture layouts, joinery heights and lighting should all keep the sightline clear. A tall cabinet or a pendant in the wrong place can cut a view in half.
Glare and heat matter as much as the outlook. Window treatments, blinds and the choice of reflective or matte finishes near the glass are part of the design, not an afterthought.
Volume and proportion
Many penthouses have generous ceiling heights or double-height areas. Standard furniture can look lost in them, and a room that feels grand when empty can feel unfinished once furnished. Scale the key pieces to the room. Our guide to custom furniture or off-the-shelf covers when bespoke pieces earn their place.
Services, kitchens and bathrooms
Kitchens and bathrooms are tied to the risers. Moving them a few metres can mean longer drainage runs, raised floors or changes the building may not accept. Decide early whether the existing positions work. If they do, the design is freer elsewhere; if they don't, the approval question comes first.
Terraces
Terraces are often the most valuable square metres of a penthouse. Treat them as rooms, with planned furniture, lighting, shade and planting. Anything fixed, such as pergolas, outdoor kitchens or screens, can affect the building's appearance and structure, so check what the building allows before designing it.
Building rules and approvals
Penthouse works sit inside a building with its own management and rules, and interior works can need a fit-out permit from the authority for the plot. Our guide to renovating an apartment or penthouse covers the approval side.
Finishes that hold up
At this level, finishes are read at close range and under strong daylight. Review physical samples in the space itself, at different times of day. Stone, timber and metal should be specified against one physical reference so tones match across joinery, furniture and fittings.
How Ganggaan approaches it
At Ganggaan, interior design, custom furniture, FF&E sourcing, Architect of Record permitting and site supervision sit in one studio. Custom pieces are designed in-house and made by trusted partner workshops, sized to the room rather than to a catalogue.