MEP Plans in Imperial County, CA
Permit-ready mechanical, electrical and plumbing plans for ADUs, garage conversions, additions and single-family homes anywhere in Imperial County, in its cities and in unincorporated areas, with Title 24 available in the same order.
Imperial County project facts we design around
| County seat | El Centro |
|---|---|
| Population | 181,724 (Census 2024 estimate) |
| Incorporated cities | 7 |
| Unincorporated residents | About 34,281 (19% of the county) |
| Permits in unincorporated areas | Imperial County Planning & Development Services Department – Building & Safety Division |
| Title 24 climate zones | Climate Zone 15. Confirmed by ZIP for every project |
| ADU approval timeline | Approve or deny within 60 days of a complete application (state law) |
HVAC design across Imperial County
Climate Zone 15: high-desert / desert climate with extreme summer heat.
Extreme summer temperatures make cooling capacity the defining design decision, and the outdoor unit has to be rated to perform at high ambient temperatures. Cooling loads per square foot run well above coastal projects, so the electrical side follows: the AC circuit, the panel calculation, and sometimes the utility service all need to be planned around it.
- Cooling capacity and equipment rated for high outdoor temperatures
- Electrical load calculation that reflects heavy AC use
- Envelope, shading and duct decisions that keep the Title 24 margin
Unincorporated Imperial County
Unincorporated communities are permitted by the county, not by a city. County plan check reviews MEP drawings against the same California Mechanical, Electrical and Plumbing Codes and the Title 24 Energy Code as any city, but the submittal checklist, forms and fees are the county's own, so we prepare the set to match. In rural areas, parcels outside a sewer district often rely on a private septic system; adding an ADU can require the county's environmental health division to confirm the system has capacity, and the plumbing plan then shows the connection to the septic tank instead of a sewer lateral.
What's in an Imperial County MEP set
- Mechanical: HVAC layout, Manual J load calculation, equipment schedule, exhaust and whole-unit ventilation
- Electrical: power and lighting plan, panel schedule, NEC 220 load calculation, single-line diagram
- Plumbing: supply and DWV layout, fixture units, water heater, gas (if any), sewer or septic connection
- Title 24 (add-on): energy compliance for your address's climate zone, coordinated with the MEP design so the two documents agree
Pricing is flat statewide: ADU plans from $995, full ADU MEP package from $2,295, Title 24 add-on $240. Standard turnaround is 5 business days with two revisions and corrections included.
Imperial County cities and communities
| Place | Climate zone | Electric utility |
|---|---|---|
| Brawley | CZ 15 | Imperial Irrigation District (IID) |
| Calexico | CZ 15 | Imperial Irrigation District (IID) |
| El Centro | CZ 15 | Imperial Irrigation District (IID) |
| Heber (unincorporated) | CZ 15 | Imperial Irrigation District (IID) |
| Holtville | CZ 15 | Imperial Irrigation District (IID) |
| Imperial | CZ 15 | Imperial Irrigation District (IID) |
| Westmorland | CZ 15 | Imperial Irrigation District (IID) |
Shown for most addresses in each city. We also serve Imperial County's other 1 city and every unincorporated community.
Imperial County ADU MEP questions
Who issues building permits for an ADU in unincorporated Imperial County?
In unincorporated areas, home to about 34,281 residents (19% of the county), ADU and residential permits go through Imperial County Planning & Development Services Department – Building & Safety Division. Inside the county's 7 incorporated cities, that city's own building department reviews the plans instead. We prepare the MEP set for whichever office has jurisdiction over your address.
What Title 24 climate zones are in Imperial County?
All of Imperial County is in California Climate Zone 15 on the Energy Commission's ZIP-code list. The climate zone drives the Title 24 energy calculation and the HVAC sizing.
Who provides electric service in Imperial County?
It depends on the address. In the Imperial County places listed on this page, most addresses are served by Imperial Irrigation District (IID). We confirm the serving utility for every project, because service upgrades and new meters are requested from the utility, separately from the building permit.
How much do ADU MEP plans cost in Imperial County?
Our pricing is flat across California: single-discipline ADU plans start at $995, a full MEP package for an ADU up to 600 SF is $2,295, and a Title 24 report can be added for $240. Residential (single-family) full MEP packages start at $3,495. Standard turnaround is 5 business days, and corrections are included.
How long does ADU approval take in Imperial County?
California law requires local agencies, counties included, to approve or deny a complete ADU permit application within 60 days. Incomplete or inconsistent drawings are the most common reason the clock restarts, which is why MEP plans that match the architectural set, and a Title 24 report that matches the MEP design, matter.
Guides for Imperial County projects
Ready for permit-ready MEP plans in Imperial County?
Upload your architectural plans, get an instant flat price, and receive PDF plans in about 5 business days.
Start My OrderGeneral guidance, not legal advice. Population figures are Census Bureau 2024 estimates; climate zones are from the California Energy Commission's ZIP-code list, weighted by population. Requirements vary by project: confirm with Imperial County Planning & Development Services Department – Building & Safety Division or your city's building department.