Zoning gets most of the attention, but it is often something else that constrains an addition: an easement running through the yard, a protected tree, a historic designation nobody mentioned at purchase, or CC&Rs recorded decades ago. These restrictions are recorded against the property rather than published in the zoning code, which is why homeowners routinely discover them late.
Most are findable in an afternoon if you know where to look. Here is what to check before design begins.
Easements
An easement gives someone else the right to use part of your property, and it does not disappear because it is inconvenient.
Common types:
- Public utility easements along property lines for water, sewer, gas, electrical, or communications. Usually a strip several feet wide where building is prohibited.
- Access easements allowing a neighbor to cross your property, common with flag lots and shared driveways.
- Drainage easements preserving established water flow across the lot.
- Sewer or storm drain easements where a main crosses private property.
Easements are recorded and appear on your title report and often on your plat map. The practical effect is that the easement area is removed from your buildable envelope even when zoning would allow building there. Some cities also restrict landscaping within them — a point worth knowing, since privacy screening required by design standards cannot be planted inside an easement.
CC&Rs and Homeowners Associations
Covenants, conditions, and restrictions are private agreements recorded against the property, separate from and in addition to city rules.
They can govern architectural style, materials, colors, roof form, height, fencing, and landscaping, and they may require approval from an architectural committee before you build. That approval process runs parallel to city permitting and adds time.
One important limit: HOAs cannot unreasonably restrict ADU construction under state law. They can still enforce reasonable aesthetic standards, but a blanket prohibition is not enforceable.
CC&Rs appear in your title documents. If you cannot locate them, the county recorder can.
Historic Designation
Historic status can attach at the local, state, or federal level, and many homeowners do not know their property carries it until they apply for a permit.
Designation typically brings additional review for exterior changes, and can affect window replacement, siding, roof materials, and how an addition is massed. San Francisco has a large stock of buildings classified as historic resources, and preservation review there goes well beyond standard plan check.
Some properties sit in historic districts without being individually significant, which still triggers review of street-facing changes. Check your city historic resource inventory early.
Protected Trees
Most Bay Area cities protect trees above a certain size, and some protect specific species regardless of size.
Protection generally means you cannot remove the tree without a permit, cannot damage the root zone, and may need an arborist report plus protective fencing during construction. The root protection zone often extends well beyond where people expect — commonly to the drip line or further.
A mature protected tree near your intended build area can force a redesign. Better to know at the start.
Setback Encroachments and Nonconforming Conditions
Many older Bay Area homes were built under rules that no longer apply, leaving the structure legally nonconforming — permitted to remain, but subject to limits on expansion.
The complications arise when an addition touches the nonconforming portion. Some cities allow expansion elsewhere while requiring the nonconforming area stay as is. Others require it be brought into compliance once work exceeds a threshold.
Palo Alto handles one version of this straightforwardly: where existing structures that remain do not meet the objective design standards, the structure is not considered noncomplying and the existing conditions may remain. Rules vary considerably between cities, so confirm yours.
Slope, Soil, and Geologic Constraints
Physical conditions function as restrictions too.
- Steep slope can trigger additional review, engineered foundations, and retaining work.
- Expansive soils, common in parts of the Bay Area, may require a geotechnical report and a reinforced foundation design.
- Seismic hazard zones can require geologic investigation.
- Flood zones impose elevation requirements, though they sometimes come with corresponding height allowances.
Overlay Zoning
Overlays add requirements on top of base zoning for specific areas.
Single-story overlays are the most consequential for additions — they prohibit second stories entirely. Several Eichler neighborhoods in Palo Alto, including Greenmeadow and Green Gables, carry them. In those areas, building out or building an ADU are the available paths.
Other overlays address neighborhood character, specific plan areas, or environmental conditions.
How to Find All of This
- Pull your title report from your purchase, or order a new one. Easements and CC&Rs are recorded there.
- Check your city parcel viewer for zoning, overlays, and often historic and environmental layers.
- Search the historic resource inventory for your address.
- Review your plat map for easements and precise lot dimensions.
- Identify trees near the build area and check size thresholds in your city tree ordinance.
- Call the planning counter. Most cities will answer specific questions about a parcel before you file anything.
Frequently Asked Questions
Can an easement be removed?
Sometimes, if the holder agrees to release it, but the process is slow and uncertain. Design around it unless you have confirmed otherwise.
What if I discover a restriction after design is complete?
You redesign. This is precisely why feasibility review comes before design, and why the sequence matters.
Do CC&Rs expire?
Some have termination dates or renewal provisions; many do not. Read the recorded document rather than assuming.
Can I build over a utility easement if I get permission?
Occasionally, with written consent from the utility, but many will not grant it. Do not assume.
Does historic designation prevent additions entirely?
No, but it shapes them. Additions to historic properties are often required to be subordinate to the original structure and distinguishable from it.
Checking Your Property Before You Design
Design by M&M is a Bay Area design-build company working with homeowners in Palo Alto, San Francisco, and surrounding Peninsula and South Bay communities. Feasibility review comes first in our process — identifying easements, overlays, tree protection, and historic status before drawings begin, so the design accounts for them from the start.
If you are planning an addition, a consultation is the place to start. Contact Design by M&M to discuss your property.
