Hillside Design Starts With the Slope
On a flat lot, you can usually begin with the house. On a hillside, the sensible place to begin is the ground. The slope influences where a building can sit, how it is built and how it relates to its views, and it is far easier to work with than against.
The section comes before the plan
Most people picture a house in plan, as a layout of rooms. On a slope, the more telling drawing is the section, a cut through the site that shows how the land rises and falls. A good hillside architect in Los Angeles spends time on that cut early, because it reveals where the building can sit lightly, where it will need to step, and where the ground is simply telling you not to build.
Stepping, bridging and anchoring
There are several general approaches to building on a slope. A house can step down the hillside in levels, it can sit on a pad cut into the slope, or it can reach out over the grade on structure. Each one has different consequences for foundations, retaining walls, access and the feel of the rooms. None is automatically best. The right choice depends on the slope, the soil and what the owner wants from the site, and it is confirmed by the engineers involved.
Soils and engineering
Hillside projects commonly involve a geotechnical investigation, which looks at the soil and rock and informs the foundation and retaining design. Structural engineers then design those elements. Requirements differ between jurisdictions and between sites, so the specific scope for a property should be confirmed with the local building department and the project's engineers. The architect's role is to coordinate those findings with the design from the start, so they shape the building rather than interrupt it.
Water is part of the design
How water flows across, through and off a slope is central to its stability and to its neighbors. Drainage on a hillside is not a detail to be added at the end. It affects where paths, terraces and walls go, and how the lower parts of the site are treated. Rules about drainage and grading vary by location and should be checked locally.
Access and construction
A narrow road, a steep driveway or a lot with no direct vehicle access affects how materials arrive and how the building can be built. Those realities can influence the structural system, the phasing of the work and the practicality of the design. They are worth walking through at the beginning.
A hillside house that fits its slope feels inevitable. One that fights it tends to show the effort.
Views, privacy and the neighbors
The same slope that creates a view also creates visibility. Windows that frame a canyon can look into a neighbor's terrace. Roofs seen from above matter as much as facades seen from the street. Good hillside design pays attention to what the building looks like from above and below, and where privacy is gained or lost.
Rules that apply to hillside lots
Many jurisdictions, including parts of Los Angeles, have additional planning and building rules for hillside areas, which may address size, height, grading and fire safety. These vary by location and change over time, so we do not summarize them here. Confirm the current requirements for your address with the local planning and building departments.
Starting the conversation
Our hillside architecture page explains how we approach these sites, and the FAQ answers common questions about the process. If you are still deciding on a property, read buying a hillside lot: what to check first. When you are ready to talk about a specific site, the contact form is the place to begin.
Start with the architect. Whatever the question is, the design, the permit, the budget or who to bring in next, an architect looks at the whole project first and then helps you choose and coordinate the engineers, designers and builders it needs. Talk with Kevin Cohen, AIA about your project.
General information only, not legal, engineering or code advice. Rules differ by city and change over time, so confirm the details for your property with your local building and planning departments and with qualified professionals.