Can a porch or deck extend into the setbacks in Ferndale?

Yes, within limits. Section 3.03 allows porches and decks to project into required yards:

• Front. A porch or deck may extend up to 50 percent of the way into the front setback. With a 15 foot front setback, that is up to 7.5 feet of projection.
• Sides and rear. A porch or deck may come within 3 feet of the side and rear lot lines.

Other yard features have their own rules under the same section:

• Pools and game courts are barred from front yards and need 5 foot side and rear setbacks.
• Permanent equipment, such as mechanical units, is barred from front yards.

Remember that the front setback itself may not be 15 feet on your block. The contextual averaging rule (Section 2.06 footnote D) can move it up or down, and the 50 percent projection works off whatever setback applies. Confirm your numbers with the city at 248-336-4370 before building.