Chimney rebuild in brief
A rebuild means taking the chimney down to solid masonry and laying it back up with new brick or stone and fresh mortar. Depending on the damage, that can mean only the section above the roofline or the full chimney. The job usually ends with a new crown on top, new flashing where the chimney meets the roof, and a cap. If the flue liner is damaged, liner work can be done during the same job. For the full scope, materials and sequence, read how chimney rebuild works.
Local zoning rules that shape a masonry chimney rebuild
A rebuild is the point where a chimney's size and shape can change, so limits on chimney size matter at the planning stage. The provisions below come from the Town of San Anselmo's Single Family Residential (R-1) Zoning Regulations summary and the town's Planning R-1 Zoning Regulations Handout. They apply to homes under the town's single-family zoning.
Height: up to four feet above the building limit
Under San Anselmo's single-family zoning regulations (Section 10-3.404), a chimney up to twelve square feet may exceed the maximum building height by four feet. For a rebuild, this sets the target before any brick goes up. A chimney rebuilt at its original dimensions is easier to keep inside that allowance than one that is enlarged or extended upward.
Projection: chimneys as architectural features
San Anselmo's zoning definitions treat chimneys as architectural features, defined as projections with a maximum exterior projection of two feet that add no floor area. This matters if a rebuild would make the chimney wider or push it farther out from the wall than it was before. Keeping the new masonry within the original footprint avoids that issue.
Minor exceptions: possible, but only with findings
San Anselmo's zoning regulations (Section 10-3.14.505) list chimneys and fireplaces among features for which a minor exception may be approved only after required findings are made. If a planned rebuild would not fit the height or projection limits above, an exception is not automatic. Settle that question with the town before you commit to a larger design.
| Provision | What it says | What it means when rebuilding |
|---|---|---|
| Section 10-3.404 | A chimney up to twelve square feet may exceed the maximum building height by four feet | Set the rebuilt chimney's height and size against this allowance before work starts |
| Zoning definitions | Chimneys are architectural features: projections with a maximum exterior projection of two feet that add no floor area | Avoid widening the chimney or extending it farther from the wall unless the design has been checked |
| Section 10-3.14.505 | Chimneys and fireplaces are among features for which a minor exception may be approved only after required findings are made | A design outside the limits is not automatically allowed |
Decide on dimensions first
The simplest rebuild puts the chimney back at the size and shape it had. If you want it taller, wider or reshaped, settle the dimensions before the old masonry comes down. That way the new chimney is designed to fit the rules from the start.
Rebuild or a smaller repair?
Not every damaged chimney needs to come down. These signs usually point toward a rebuild:
- The chimney leans or has pulled away from the house.
- Cracks run through the bricks themselves, not just the mortar joints.
- Bricks are loose, spalling or falling across a large section.
- Earlier patching keeps failing in the same area.
If the bricks are sound and only the mortar joints are worn, repointing the joints is usually enough. A cracked crown or failed flashing can often be repaired on its own. Our guide to chimney repair vs rebuild explains how to tell the difference. If you are rebuilding because you want a different fireplace altogether, it can help to plan the new chimney together with a new fireplace installation for your home.
Leaning or falling masonry
If a chimney is visibly leaning or dropping brick, keep people away from the area below it and don't use the fireplace.
Booking a chimney rebuild in San Anselmo
At the estimate, we look at the chimney's condition and decide with you how much of it needs to come down and how it should be rebuilt. You can read more about our chimney rebuild service, or browse all our services in San Anselmo. When you're ready, call or request an estimate.
Free estimates.
Call or request an estimate to have your chimney looked at and the rebuild planned.
Sources (1)
The sources of the San Anselmo facts on this page.
- 1Town of San Anselmo - Single Family Residential (R-1) Zoning Regulations summary (through 8/28/2026); Town of San Anselmo Planning - R-1 Zoning Regulations Handout
