Accessory Dwelling Units

(updated April 8, 2024)

This area of zoning regulations has continued to evolve since the City of Santa Cruz began to liberalize the rules in 2014. Since then, the state has adopted rules very similar to Santa Cruz, requiring all cities and counties to follow suit. As a result, the County adopted new rules in March, 2018 (Ordinance No. 5264 and 5265). Some requirements that used to be ADU project-killers have been removed, but the new ordinance also creates some new complexities. While working on a "decision tree" for my own use in ADU project planning, here's a preliminary pro/con look at some of the new provisions:

Pro:

• Most ADUs now require only a Building Permit (with some important exceptions, see "Con:")
• Allowable locations for "Conversion ADUs" liberalized. For instance, conversions previously had to meet the same property-line setbacks as the main residence, which excluded many detached garages. 
• For Conversion ADUs and in many other situations, it's no longer necessary to provide an extra on-site parking space for an ADU (especially important for small lots). Tandem parking rules are also liberalized.
• Fire sprinklers are not required for an ADU where they aren't existing/required for the main residence.
• Sewer and water hookup fees are no longer charged for ADUs when such new hookups are not actually constructed.

Con:

• New "Site and Structural Dimensions Chart" shows eight different categories of ADU, making it trickier to successfully plan an ADU project.
• Some zones still require higher-level permits:
• CA (Commercial Ag) zones still require a level 4 (outside Coastal Zone) or level 5 (inside Coastal Zone) permit. All ag zone ADUs still require approval from the Ag. Policy Advisory Commision, a public hearing.
• In some Coastal Zone locations, a coastal permit is still required.
• Owner residency still required
• Short term/vacation rental not allowed in an ADU.

Homeowners Guide

Check out the new Homeowners Guide page (link in the list at right). The aim is to help owners understand the process of building/adding/remodeling/altering residential properties in Santa Cruz County. It's very much a work-in-progress, so check back periodically.

Thanks to the Santa Cruz Construction Guild for including a link to the page from the Guild website's Homeowner Advice page.

Plumbing fixture retrofit mandate in California

For those of us (everyone?) who failed to study the 2013 California Title 24 codes prior to their implementation in 2014, more and more of the changes wrought are showing up in building permit plan reviewers' comments. Some of these changes have also found their way into the state Civil Code, which can require actions not tied to building permit applications. One set of such changes is found in Section 1101, relating to mandates to upgrade existing building plumbing fixtures. 

There are two implementation dates, one past and one still in the future. Since January 1, 2014, approval of any kind of building permit on a single-family residence required upgrading all plumbing fixtures in the house to meet current low-water-use standards. This permit-approval-based whole-house retrofit requirement is similar to what we've seen for a number of years with smoke alarms.

The future important date, however, applies to existing multifamily and commercial properties and is not triggered by building permit applications. On January 1, 2019, all multifamily and commercial properties are supposed to have completed low-water-use retrofits throughout their buildings. For a large apartment complex, that's a lot of plumbing fixtures!

One odd feature of these new rules is that they only apply to buildings built before 1994. Presumably, an earlier low-water-use standard toof effect that year (not verified), so building projects after that date would already have such fixtures. Follow the link here to read Section 1101 for yourself.

Energy Upgrade California and EnergyPro, part 2

I followed up on what I learned in the January 20 workshop by contacting a fellow Santa Cruz Construction Guild member, General Contractor Scott Milrod. Scott is very involved these days with home energy upgrade projects, and is qualified as a participating contractor in the EUC rebate program. It turned out that Scott had already started on a demonstration project with Ecology Action. The EUC rebates come in two “flavors”:

• Basic – a $1,000. rebate given for installation of a prescriptive package of energy-efficiency upgrades.
• Advanced – a $1,000 – 4,000 performance-based rebate. The amount awarded is determined by the amount of improvement (reduction in household energy cost). The contractor and homeowner can choose from a wide variety of improvement measures. Choices are customized to fit the individual situation.

The required “as-built” testing and EnergyPro modeling were complete, so the work remaining to be completed before submitting a “pre-installation” application for a rebate was the dreaded paperwork. That’s where I was able to get involved and help out, while learning about the process. Actually, “paperwork” is an outdated term, since all of the required forms can be completed and submitted online. This “paperless” process is available through the EUC website, which was set up by the CEC to be a “one-stop shop for energy upgrades”, including rebate and incentive programs all over the state. For our demonstration project, the application process involved completing and submitting the following:

1. An on-line, guided application form.
2. At least one year’s worth of energy use/cost data. In this case that meant natural gas and electricity use data from PG&E.
3. An EnergyPro model of the house, first with the existing conditions, then with the proposed improvements
4. The contractor’s proposal to the homeowner
5. A test measurements form, created by PG&E, for recording safety-related test data, such as interior CO emissions from gas appliances.
6. An Excel worksheet containing much of the same data as the online application.
7. A copy of an authorization form, signed by the homeowner, giving EUC permission to use the energy data in the rebate application process.

All of this was completed a couple of days ago. Now we wait for the application to be reviewed. When that happens, I’ll give you all an update. Another future topic that may be of interest is a discussion of the kinds of home energy upgrade products and methods that are available these days. Energy costs are a concern to everyone these days, so it’s important for designers and contractors to be able to address clients’ needs in this area.

Energy Upgrade California and EnergyPro, part 1

On January 20, I attended the morning session of an EnergyPro / Energy Upgrade California workshop. I have used EnergyPro for many years to do T24 compliance calculations and documentation for building permit submittals, so I was interested in learning about new uses for a very good software program. The workshop explained how EnergyPro can be used to analyze the benefits of upgrades to home energy-efficiency measures; things like adding insulation, fixing leaky heating ducts and replacing old furnaces and windows. The Energy Upgrade California program offers rebates to homeowners for qualifying improvements. Requirements for documenting such improvements are fairly technical - that's where EnergyPro can help. The software includes extensive capabilities to model a wide range of energy-efficiency improvements, and the ability to generate reports for documentation.

The workshop did not assume any prior knowledge of EnergyPro, so the morning session was spent in a basic introduction to the workings of the software. It seemed to me that about one-third of the attendees were already familiar with EnergyPro, so there was not too much new information for us. Of interest to me was instruction on the use of some sections of the software I'm less familiar with, including detailed modeling of HVAC system features. For my usual T24 compliance work, it's not necessary to go into such detail in that area.

I was sorry that I could not stay for the afternoon workshop session, which got into the actual production of Home Energy Assessment reports, and others required for the Energy Upgrade California rebate program. Energy analysts for the rebate program are required to possess knowledge, which I currently lack, of various testing procedures to show before/after improvements in energy efficiency. However, the preparation of a Home Energy Assessment report can be a very effective sales and marketing tool in itself. The report shows homeowners how much money they can save on their energy bills by installing specific energy-saving measures. I plan to get into that area, in partnership with contractors equipped to do the necessary testing.

Conventional Construction: Selecting framing lumber

Wood is the most conventional of materials, and lumber is the wood used in conventional construction. Not just any lumber, though – as noted previously, lumber must be standardized and pre-approved in several ways. Also, allowable size and spacing of framing members are prescribed. The building code (CBC) simplifies the selection of conventional structural lumber by providing tables, organized by intended use. One thing you'll notice about the tables is that only a few wood species and sizes are included. For other choices, an online selection calculator from the American Wood Council is available here. If you use this tool, be sure to verify your selection with your inspector or building official.

The image at left shows the title of the first of two tables for selection of floor joists. The difference between the two tables is enclosed in parentheses below the title: (Residential sleeping areas, live load = 30psf…). The other table is for: (Residential living areas, live load = 40psf…). This split table is a change from the previous code; using different live load (mainly people and furniture) values for living and sleeping areas.

Just below the title is the header section of the table:
The header shows several important variables. The first is dead load, which is the weight of installed materials supported by the joists. The old code had a table giving weights of many different materials, but there’s really only one common situation that might call for using a dead load = 20psf – that’s heavy flooring like mortar-set tile. Another situation where using 20ps might be a good idea is if you know the room is going to be used for something like weight-lifting. In the following example, we'll use only the 10psf side of the table.

To use the table, start with the desired span, then move out to the edges to find size, wood species and spacing. For example, say you have a 14’-0” span. On the left half of the table (dead load = 10psf), find the span numbers closest to but not less than 14’-0”. For simplicity, we’ll stick to the most common (in Santa Cruz) wood species, Douglas fir (D.F.). Grade #3 is not commonly available, so we’ll ignore that also. As a designer, I would conclude that the three best conventional size/grade/spacing options are:

2x8 #2 @ 16” (rectangles added to highlight choices)

2x8 SS @ 19.2”

2x10 #2 @ 24”

At this point, you can plug these three into your estimator software along with current prices and go with the most cost-effective choice (note also that, for the contractor, current prices and/or labor costs might point to a choice other than these three). Cost aside, sometimes there are design reasons for preferring one size or spacing over another, but that’s a topic for another time.

Conventional Construction: When Does It Become Unconventional?

Designers and contractors wishing to keep projects conventional obviously must avoid the unconventional. That's one of the main objectives of the pre-proposal feasibility research. It’s no fun explaining to clients the need for expensive structural analysis after they agreed to a proposal based only on conventional design (of course, proposals that don’t allow for unexpected discoveries later on should also be avoided).

Neither is it any fun for a contractor to make what seems like a minor client-requested design change in the field, only to be told by the Building Inspector that the project must now be engineered. Something about that minor change caused the project to cross an invisible line into the unconventional zone.

It can be a very fine line indeed between conventional and unconventional, so a thorough understanding of the determining factors is important. Previous posts have discussed a few of the general factors. Also, some situations are more perilous than others, so we'll try to cover as many of those as possible. 'Dividing line' situations fall into three categories: materials, methods and conditions.