Your question and the explanation ask two different questions that have two different answers.
Your question asks if it's ethical/acceptable to USE templates for clients. The answer is yes. Most developers without design experience do exactly that. As long as you're offering some transparency about it to your clients, this should not be an issue.
However, modifying and selling free templates (on their own, and not part of a web development package/service) may not be legal, much less ethical. It depends on the template's license. Most template authors do not allow their products to be resold commercially, though you are usually free to modify the template for an individual client.
See the difference?
For reference, check out the GNU GPL information: https://opensource.org/licenses/GPL-3.0
If the templates were acquired legally, and if you are permitted to sell them on as part of a service, then ethics has nothing to do with it. You are providing your client with a cost effective solution.
A client wants someone to be responsible for implementing a solution
They have a choice
- Pay you to re-invent the wheel.
- Pay you to get a ready made wheel.
So long as you don't steal or use someone else's work without their permission, you have not broken any ethics.
Think if your customer needed a database - would you ask the same question? Would you be asking if you should develop a new database from scratch, or use MySQL or something similar?
Best of luck!
Good question. I have always informed people that I am using a template, because one way or the other, they will find out. It benefits everyone to keep the use of these kinds of tools transparent so that people can see the difference between the tools, the talent, and the required skills. Some clients might not want to pay for anything too fancy, just the fundamentals and if you can provide that, then you've done your job. Templates like Foundation or Bootstrap make it easy to meet that criteria. I think web ethics (like any technology) will continue to go back to the balance of respecting client knowledge and providing the desired level of service which they need and which you can offer :)