Due Diligence Checklist & Resources for North County San Diego Real Estate Buyers


In all property transactions, the “rubber hits the road” once the seller accepts your offer and you enter escrow. During this phase of the purchase, it’s your opportunity to learn more about the property you are buying and to verify that it meets all your requirements. In the normal process, it’s customary for a buyer to hire a qualified home inspector who will provide a report on the physical condition of the home. Typically, there will also be a specialized pest and termite inspection that will detail any issues with infestation or rot. If you are financing the purchase, your lender will order an appraisal to validate your offering price by comparing it to recent sales prices of similar homes in the area. If you are a cash buyer, you can order your own appraisal. And there are additional steps along the way.

Prior to close of escrow, you will also receive a preliminary title report and a State of California mandated Natural Hazard Disclosure Report. Additionally, if your home is in a planned development and subject to homeowner association (HOA) governance, escrow will typically provide you with the association’s documents. If you don’t receive these documents, make sure you ask for them.

You should review and analyze each of the reports or documents to make sure they meet with your approval. In many cases, these standard reviews will provide you with an accurate picture of what you are buying. However, depending on your circumstances and inclination, there are many additional steps you can take to understand more about the property you are buying. Each additional step takes time and attention, but sometimes the hardest part is locating the resource for the information you seek. That’s why, below, we’ve compiled this list of short-cuts to additional commonly researched real estate due diligence topics.

Please Note: Real estate agents are prohibited from providing legal advice and this includes legal advice related to due diligence matters. If you don’t have the time, interest, or ability to do more extensive due diligence and investigation, you can optionally hire an attorney or other expert to do this work for you. Each property is unique.This checklist may not include all relevant issues. Where appropriate, consult with a real estate attorney to make sure you have considered all relevant issues. 

Additional Resources

1. To Verify Zoning

A zoning verification will provide you the assurance that the current or intended use for a property is legal under the current zoning. The easiest way to accomplish this is to visit the zoning department of the jurisdiction where the property is located. You will need the Assessors Parcel Number (APN) for the property when meeting with staff.

For Incorporated Cities:

If the property is in an incorporated North County city such as Oceanside, Escondido, Carlsbad, Vista, San Marcos, Encinitas, Poway, Solana Beach, or Del Mar consult that jurisdiction’s local zoning department.

For Un-Incorporated Communities (i.e. Fallbrook or Bonsall):

If the property is in an un-incorporated community in the County including Fallbrook, Bonsall, Rainbow, Valley Center, Rancho Santa Fe, Fairbanks Ranch, Ramona, San Diego Country Estates, Lake San Marcos, or Hidden Meadows, you can obtain zoning information through the County of San Diego Department of Planning and Land Use. The easiest way to learn about the zoning in these un-incorporated communities is visit the County in person.

County of San Diego Department of Planning & Development Services (Website)
5510 Overland Drive #210, San Diego, CA 92123
Zoning Information (858) 565-5981 (Automated Assistance — Staff takes calls only between 8 AM to 11:45 AM Monday through Friday)

Online Resources (County of San Diego Only)

As an online alternative to an in-person visit, you can visit the Self-Service Report Center. For quick zoning information go directly to the Property Summary Report parcel number entry screen. Alternatively, follow this link to access the county PDS Parcel Zoning and Land Use Information Tools, (or click here to go directly to the interactive map) then enter the property street address. (You may also be able to enter the parcel APN number — The APN = Assessor’s Parcel Number. The APN for your property will be provided on the MLS listing sheet. If you don’t have the MLS Listing Sheet, feel free to ask our team for help).

Once you have this the zoning information for the parcel, you can determine which ordinances apply. For the novice, there is no easy or quick way to interpret the zoning codes that are displayed, but with some fiddling you can cross-reference the codes by downloading and searching the appropriate sections of the San Diego County Zoning Ordinance.

Buildings: To determine what types of buildings are allowed on a parcel, refer to Part Two of the ordinance:

Animals: To determine what types of animals are allowed on a parcel, refer to Part Three of the ordinance:

• Businesses: To answer questions about what types of businesses (and uses, sign ordinances, etc) are allowed on a parcel, refer to Part Six of the ordinance:

Fallbrook Special Zoning: To answer specific questions related to special zoning in the VILLAGE of Fallbrook, refer to Part Eight of the ordinance:

Residential and Agricultural Accessory Structures: For specific information about legally permitted accessory structures including barns, greenhouses, guest houses, “second dwelling units”, etc, please refer to the provisions” in Part Six of the ordinance – Accessory Use Regulations – Section 6156. Specific information regarding guest houses and second dwelling units will be found in paragraphs “k” and “x or section 6156. Here is the County’s webpage with more information. (The County has also prepared a summary document : Accessory dwelling unit (ADU) handout, which may apply.)

Recreational Vehicle Use and Storage: Trailers, boats, motorhomes and other types of RVs can often be stored on many properties in the County of San Diego, but be aware that there are still potential restrictions. Homeowner associations sometimes prohibit or restrict storage of RVs. The County also has detailed guidelines that limit or regulate the use or storage of RVs on private property. For the most part, occupying or living in an RV on private land is prohibited. For more information about RV usage and storage (as it pertains to land usage and zoning) in the County consult Section 52.2 of the San Diego County Code of Administrative Ordinances.  (Click here to link to the San Diego County Code of Administrative Ordinances and then enter “52.201” in that site’s search box. Note: there may be other ordinances, regulations, or laws that apply).

• “Commercial” Horse Stables: In 2013 the County of San Diego revised their ordinances regarding commercial horse stables, which includes regulations on the boarding of horses not owned by property owner. More information about the these revisions can be found here.

Land Clearing and Alteration: Before purchasing land where you contemplate undertaking significant projects on wetlands, floodplains, steep slopes, sensitive biological habitats, and prehistoric and historic sites, you should review the County’s Resource Protection Ordinance.

Like most regional governments, San Diego County’s zoning and regulatory ordinances are complex. It helps to keep in mind that land use is governed by many factors including those contained in the entire zoning ordinance.

(Hint: To quickly find the definition for a zoning “use code” found in your search results, use your PDF reader’s search tool to search the document by keyword.)

2. To Verify Building Permits

A building permit verification will provide you the assurance that each structure on the property has been permitted by the county and matches the current, as-built, square footages and features.

For Incorporated Cities:

If the property is in an incorporated North County city such as Oceanside, Escondido, Carlsbad, Vista, San Marcos, Encinitas, Poway, Solana Beach, or Del Mar you must consult that jurisdiction’s local Building Department.

For Un-Incorporated Communities (i.e. Fallbrook or Bonsall):

If the property is in an un-incorporated community of the County including Fallbrook, Bonsall, Rainbow, Valley Center, Rancho Santa Fe, Fairbanks Ranch, Ramona, San Diego Country Estates, Lake San Marcos, or Hidden Meadows, you can obtain building permit history through the County of San Diego Building Department.

To speak directly with a county building tech who can answer questions about permits and permitting contact:

County of San Diego Building Division (Website)
5510 Overland Drive #210, San Diego, CA 92123
(858) 565-5920 (8 AM to 4 PM (closed for lunch)
or toll free at (888) 336-7553

You can also use the online alternative for checking status on most permits issued in un-incorporated areas since 1989 by searching the County of San Diego’s online Acella Citizen Access Database for Planning and Development Services (PDS). Once on the main screen, click the PDS tab. (see instructions & tips below).

(Tips on using ACELLA: You can search records by parcel number or street address (and other ways too). After selecting the “PDS” search screen tab, enter the property identifier in the correct field within the online form. Please note that when searching by parcel number, the correct entry format for the Assessor Parcel Number (APN) is always 123-456-78-90; The search tool requires that you use dashes and the number of characters in the correct format. Remember — to assure that you search all records back to 1989, make sure you delete the “start date” for the record search. Just leave that field blank. For complete system help, click here.)


For older permits issued from 1973 to 1989 the County maintains microfiche records which can be obtained in person by visiting the County’s Building Department at 5201 Ruffin Road. For building permits issued before 1973 you will need to go to the The San Diego County Recorder’s Office and ask for the Property Records recorded for each parcel in the County. To access the Property Record file at the County Recorder’s Office you will need written authorization from the current owner. The County provides a form which you can use for this purpose. You can download and print the form here: Authorization To View Property RecordsAsk the current owner to sign and return this form to you. Then take the signed form in-person to your nearest San Diego County Recorder’s Office for processing.

San Diego County Recorder’s Office
County Assessor
San Marcos Branch
141 E. Carmel St., San Marcos, CA 92078
(760) 940-6868 (press 4)

Quick-link to: San Diego County Building Forms and Handouts

3. To Verify Septic Permits (If applicable)

Many rural homes are still on septic systems. These systems are like any other appliance in your home. You should be familiar with your systems design and capabilities. In addition to having the septic system inspected by a qualified technician, you should also verify that the system has been permitted and appropriately sized for the property. If you plan to remodel or improve the home, you should also determine the limitations and issues with the current septic system.

This is the website for the San Diego County Department of Environment Health (DEH)

Click here to access the Online Library for Land and Water Quality Records. Using this online portal, you can obtain permitting status on septic systems within SD County jurisdiction. You can search by APN, address or permit number. It’s often easiest to look up a property by address, just make sure you enter the street number and street name separately in the search boxes.

Alternatively — To obtain county records and permit history by phone, please call: 858-565-5173. When you reach the county clerk, you must provide the Assessor Parcel Number (APN) (or in some cases the street address may be sufficient) for the property you are researching. Tell them you are researching the septic permit history for this property. County staff will then pull the property file, provide feedback to you on the septic permits, and if requested they can scan and fax appropriate documentation for your records.

4. Finding APNs

If you find it necessary to search county records using an Assessor Parcel Number (APN) you’ll first need to determine that number. This can be obtained in a number of ways.

1. San Diego County Lookup Tool: https://sdgis.sandag.org/ 
Once you’ve obtained the APN, and before entering this number into the DEH search portal, you must convert the number to the format required, which is xxx-xxx-xx-xx. Insert dashes into the number to match the required format.
2. Zillow:  Enter the address at Zillow.com. Once you’ve found the target property on Zillow.com, scroll to the heading “Facts and Feature” where you’ll see at the bottom of the section a link that says “See more facts and features.” Click this link and scroll down until you see “Property Details”. You’ll then see the Parcel # for this property.

5. To Determine The Cost to Bring Electrical Power To Vacant Land or Unimproved Parcels

Geographical Planner
Project Management Department – 877-789-9866

6. Understanding Road Maintenance Agreements

To learn more about private roads and agreements to maintain these roads, click here

7. You Can Consult A Variety of Online Maps

Learn more about San Diego County by using government provided maps at SANGIS SD County mapping portal (go to SANGIS Home to access City of San Diego and incorporated communities.)

8. Consider Review of Private 3rd Party Services

Symbium: Symbium’s goal is to make the zoning and planning regulations easier to navigate. Go to Symbium.com. (CAUTION: Do not rely on this data. Always consult official governmental authorities and resources.)

9. You Should Consult with an Attorney To Determine If Additional Due Diligence is Advised

Published on Tuesday, September 20, 2011

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