Adding living space in Los Altos or Los Altos Hills begins with a clear picture of what the existing home does well and what needs to change. An addition may also affect circulation, outdoor connections and adjacent rooms. We discuss those connections as part of the construction scope, with design coordination included within the project rather than offered as a standalone service.

Discuss your Los Altos & Los Altos Hills project ↗

Confirm the jurisdiction before using a checklist

Los Altos and Los Altos Hills are separate jurisdictions, even where postal names and ZIP codes overlap. Los Altos describes Planning approval before building review for additions and new single-family dwellings. Los Altos Hills has its own Building Department and submittal information. Confirm the property’s jurisdiction and current instructions before assembling a plan set.

Prepare for the construction conversation

Identify the city or town responsible for the property, not just the mailing address.
Explain how the new space will connect to the existing kitchen, bedrooms, circulation and yard.
Ask the design team to identify the drawings and structural information needed to price the addition together with any adjoining remodel.

Can an addition be priced separately from the existing-house work?

Separate line items can help, but the connection between old and new work still needs a coordinated scope. Ask what is included for structural connections, utilities, finishes at the transition and repairs to affected rooms, and record exclusions before comparing proposals.

Construction services for your home

Explore our home additions approach, ADU construction and design coordination within construction projects. Scope, pricing and schedule are confirmed for each property; a website guide does not establish approval to build.

See how homeowners describe the experience

Explore San Jose: renovating a 1962 home for a closer look at the project scope and the homeowner’s experience.

Official local planning resources

Planning resources checked October 30, 2026. Requirements can change; use the current jurisdiction guidance for your property.

Tell us about your property

We serve selected neighborhoods within our listed communities. Share your address, available plans, project priorities and preferred timing so we can confirm coverage and discuss next steps. Send a project inquiry or call (650) 787-5802.