---
title: "Energy Efficient Roofing in Tarzana, CA | NEMA Roofing"
description: "Energy efficient roofing in Tarzana: cool roof ratings for zone 9, radiant barriers, attic ventilation, insulation, ducts and solar planning at reroof time."
url: "https://nemaroofing.com/green-eco-friendly-roofing/energy-efficient-green-eco-friendly-roofing-in-tarzana-california/"
updated: "2026-09-29"
---

**Energy efficient roofing in Tarzana means a roof assembly that keeps summer heat out of the house: a cool-rated surface that meets the climate zone 9 values, a radiant barrier or insulation at the deck, balanced attic ventilation, a sealed and insulated ceiling, and air-conditioning ducts kept out of the hottest air.** The surface alone is only part of it. To have your roof and attic looked at together, call NEMA Roofing at [818-528-6412](tel:818-528-6412).

## How much heat does a Tarzana roof face?

The NOAA weather station at Pierce College in Woodland Hills, about 2 kilometers from Tarzana, records an average August high of 97.4 degrees Fahrenheit, about 115 days a year at 90 degrees or above and about 35 days at 100 or above (1991 to 2020 normals). Annual rainfall there averages 16.4 inches. That makes Tarzana a cooling-first climate, and the roof is the largest surface of the house facing the sun.

The housing stock matters too. Census estimates for ZIP 91356 show about 78 percent of Tarzana’s homes were built before 1980. Many of those attics still have their original insulation and vents, so a reroof is the natural time to check them.

## What the numbers on a cool roof label mean

- **Solar reflectance** (0 to 1): the share of sunlight the surface reflects. Higher is cooler.
- **Thermal emittance** (0 to 1): how well the surface sheds the heat it does absorb.
- **Solar reflectance index (SRI)**: one number combining the two.
- **Aged values**: ratings measured after outdoor weathering, listed in the Cool Roof Rating Council directory. The energy code counts only these, because a roof loses some reflectance as it weathers and collects dirt.

For a Tarzana reroof that replaces more than half of a sloped roof, the minimum is an aged reflectance of 0.20 with emittance of 0.75, or an SRI of 16. Flat and low-slope roofs need 0.63 and 0.75, or an SRI of 75. Los Angeles Department of Building and Safety (LADBS) requires a rated product on residential replacements over half the roof. Our [cool roofing service](https://nemaroofing.com/our-services/cool-roofing/) covers rated products in detail.

## Where heat gets past the roof, and what stops it

| Layer | What it does | What to check |
| --- | --- | --- |
| Roof surface | Reflects sunlight and sheds absorbed heat | Aged rating of the exact product and color |
| Radiant barrier | Cuts heat radiating from the hot deck into the attic | Installed facing an air space, not buried in insulation |
| Attic ventilation | Carries hot air out at the ridge, draws cooler air in at the eaves | Balanced intake and exhaust; ember-resistant vents in fire zones |
| Air sealing | Stops attic air leaking into rooms | Gaps at top plates, attic hatches, recessed lights and pipe chases |
| Ceiling insulation | Slows heat moving from attic to rooms | Depth and coverage; R-38 is the level the code names |
| Ducts | Carry cooled air through the attic | Sealed and insulated, or moved into conditioned space |

Each layer covers for the others. A reflective surface over a leaky, uninsulated ceiling still lets heat in; a well-insulated attic with no ventilation still overheats the deck and shortens the life of the roofing.

## Why the code lets some houses skip the cool surface

California’s energy code (Title 24) treats the attic as an alternative to a reflective roof. In climate zone 9, a steep-slope reroof does not need the cool-roof values if the house has R-38 ceiling insulation, a radiant barrier in the attic, no ducts in the attic, or insulation of at least R-2 at the roof deck. Roof area covered by building-integrated solar panels is exempt as well (ordinary rack-mounted panels do not exempt the roof beneath them).

That gives a real choice. If you want a darker, non-rated color, upgrading the attic can meet the rule and still cut heat gain. If the attic is already good, a cool surface adds a further margin. On a house built before 1980 with thin insulation and ducts in the attic, doing both usually brings the largest comfort gain.

## Flat roofs over additions and garages

Low-slope sections often have little or no attic space above the ceiling, so heat from a dark surface reaches the room below quickly. A white or light single-ply membrane with tapered insulation underneath addresses both heat and drainage. The code allows a lower reflectance on low-slope roofs when enough continuous insulation is added, which suits a room where you want the insulation anyway. See our [flat roofing service](https://nemaroofing.com/our-services/flat-roofing/).

## Planning for solar at reroof time

1. Put the new roof on first, so panels are not removed and reinstalled for an early reroof.
2. Choose a roof expected to last at least as long as the panels.
3. Mark attachment points on the rafters and plan conduit routes before the covering goes on.
4. Keep the array clear of shade from trees and neighboring roofs.

## Fire zone details that keep the efficiency

Parts of ZIP 91356 are mapped as a Very High Fire Hazard Severity Zone on CAL FIRE’s 2025 map and the City of Los Angeles fire zone layer, and LADBS requires a Class A roof covering there. Efficiency and fire safety fit together: ember-resistant vents keep the attic ventilating, closed eaves and bird stops at tile edges block embers, and cool-rated shingles, tile and metal can all be specified as Class A assemblies (confirm the listing for the exact product).

## Keeping an efficient roof efficient

A reflective roof works only while it stays clean; the EPA notes that low-slope cool roofs in particular need periodic cleaning to keep their reflectance. Clear valleys, gutters and drains, and check ridge caps and edges after strong winds. Our guide to [roof maintenance in Tarzana](https://nemaroofing.com/green-eco-friendly-roofing/green-eco-friendly-roofing-maintenance-in-tarzana-california/) has the full routine, and [eco-friendly roofing materials in Tarzana](https://nemaroofing.com/green-eco-friendly-roofing/green-eco-friendly-roofing-materials-in-tarzana-california/) compares the coverings.

During a reroof we can walk you through the attic to show where heat gets in and what each fix does. Tarzana is one of five NEMA Roofing locations, with Santa Barbara, Oxnard, Woodland Hills and Downey, and our teams cover every part of Los Angeles, Ventura, Santa Barbara, Riverside and San Bernardino counties; see our [Tarzana roofing page](https://nemaroofing.com/service-areas/roofing-services-tarzana-ca/) and [eco-friendly roofing service](https://nemaroofing.com/our-services/green-eco-friendly-roofing/). For an energy-focused roof plan, call [818-528-6412](tel:818-528-6412).