Can I use the original plans for my house to get a renovation permit?

Original plans can be a helpful reference, but the new permit drawings must show existing conditions accurately. The design team usually verifies dimensions and later changes on site before preparing new drawings. Whether any parts of the old set can be reused depends on their accuracy and on what the building department requires for your project.

How do I find the permit history for my Los Angeles property?

For property in the City of Los Angeles, LADBS offers an online building records search where you can look up permits and some archived documents by address. Older or unscanned records may need to be requested from the department. If your property is in another city in LA County, check that city's building department.

What are as-built drawings?

As-built or measured drawings show a building as it actually exists, based on site measurements rather than the original design. They are the most reliable basis for renovation design when they are recent and complete. Older as-built drawings still need a check for changes made since they were prepared.

Using Existing Drawings for a Renovation: What to Verify

Using existing drawings for a renovation can save time and money, but only after they are checked against the building as it stands today. Old plans may show an early design rather than what was built, and later changes are often missing. This guide explains how to organize old drawings, verify them on site and research permit history before they become the basis for new work.

What counts as existing drawings for a renovation

Existing drawings come in many forms. You may have the original permit set, a builder's plan, a previous owner's remodel drawings, a real estate floor plan or as-built drawings made by measuring the building.

Each has a different level of reliability. A stamped permit set shows what was approved, which is not always what was built. A marketing floor plan is useful for orientation but rarely accurate enough to design from. True as-built or measured drawings are the most reliable, as long as they are recent and complete.

Identify the source, date and version of each file

Before sending drawings to anyone, sort them. For each file, note:

Where it came from, such as the seller, a past architect or the city
The date and any revision number or stamp
Whether it is a design set, a permit set or measured as-built drawings
Which parts of the building it covers
Anything you already know is different today

Keep complete sets together. Mixing pages from different revisions is one of the easiest ways to create confusion later. If several versions exist, label them clearly and send them all, so the design team can decide which is relevant.

Research permit history

Permit records show what work was approved for the property and when. For property in the City of Los Angeles, LADBS provides an online building records search where you can look up permits and some archived documents by address. Not every document is online, and older records may need to be requested from the department. Properties in other cities have their own building departments and record systems.

Permit history helps in two ways. It shows which additions or conversions were permitted, and it can reveal work that was done without permits. Unpermitted work may need to be documented, corrected or legalized as part of a new project, so it is better to find out early.

Share what you find with your design team, including dates and permit numbers.

Verify dimensions and conditions on site

Even good drawings need a site check. Walls move during construction, rooms get remodeled, and equipment is replaced. Before the old layout becomes the basis for new drawings, the design team will usually confirm key dimensions and conditions.

Expect them to check room sizes, wall locations, ceiling heights, window and door openings, stair dimensions and roof lines. For structural changes, a structural engineer may need to confirm the size and direction of framing, the foundation type and whether the building sits on a slab or a raised foundation with a crawlspace.

Some conditions are concealed. Where plumbing, wiring, framing or ductwork matter to the design, small investigative openings may be needed. The drawings should show which information was verified and which is assumed.

Common gaps in old drawings

Older drawing sets often leave out exactly the information a renovation needs. Knowing the usual gaps helps you set expectations for the verification work.

Structural information is frequently thin or missing, especially for older homes. Framing sizes, beam locations and foundation details may not be shown at all, and the engineer may need to look at the actual structure.

Mechanical, plumbing and electrical systems are usually shown only in outline, if at all. Drain routes, vent locations, duct runs and panel capacity typically need to be confirmed on site.

Site information can be outdated. Property lines, setbacks, trees, grades and neighboring structures may have changed, and a new survey may be needed for work near the edges of the lot or for an addition.

Finally, old drawings reflect the codes of their time. A new project must meet current requirements where the work triggers them, so the design team will review the building with today's rules in mind.

Mark what has changed since the drawings

Help the design team by documenting differences you already know about. Walk through the property and photograph:

Rooms that were added, combined or divided
Garage or attic conversions
Moved or new kitchens and bathrooms
Replaced windows, doors or skylights
New HVAC, water heater or electrical panel locations
Decks, patios and exterior structures

Mark the rooms that are part of the new project on a copy of the drawings. This keeps the verification effort focused where it matters.

Decide what the new drawing set must do

Existing drawings are a starting point, not the deliverable. Be clear about what you need next: measured drawings of existing conditions, layout options, a permit set, or coordination with a structural engineer.

Drawings are prepared by the appropriate licensed or qualified professionals for your project. Chain Construction coordinates those professionals and the construction work, which is performed through our licensed construction partner. Ask for the proposal to list deliverables, review stages and how revisions will be tracked, so no one builds from an outdated sheet.

What we need from you to quote it

All existing drawing sets, labeled with source and date
Permit numbers or records you have found
Photos of every area in the project and the exterior
A list of known changes since the drawings were made
A short description of the renovation you want

Send these to Chain Construction or call (213) 519-8066. We will review what you have and explain what needs to be measured or confirmed first.

Using old or as-built drawings for a renovation: what to verify first