Yes — you'll create a free account to use InHouse. Sign up with your email (or a connected sign-in option) at app.tryinhouse.com. It takes under a minute and there's no charge to create an account.
Here's the order of things:
Create your account — email or a connected sign-in.
Explore right away — sample spaces and the marketplace are open to you for free.
Add your address when you're ready to twin your own home (that's the $49 step).
You must be 18 or older and in the United States to use InHouse. Trouble signing in? See "How do I reset my password?"